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Equine MOD Flashcards

1
Q

When you passport a horse what else must you do?

A

Microchip it

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2
Q

Does a foal need a passport if it’s being sold before it’s 6 months old?

A

No but the new owner has 30 days to get one

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3
Q

When does a foal under 6 months need a passport?

A

Export without its mum or sent for slaughter

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4
Q

Where is a microchip inserted?

A

Nuchal ligament, left hand side of neck

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5
Q

By when must a horse have a passport?

A

By the time its 6 months old or by 31st December of the year it’s born (whichever is latest)

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6
Q

How does the caudal maxillary sinus communicate with the frontal sinus? (horse)

A

Via the frontomaxillary sinus

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7
Q

Where do the rostral maxillary sinus and ventral conchal sinus drain?

A

Into middle meatus of nasal cavity via nasomaxillary aperture

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8
Q

Horses have a huge reservoir of RBCs where?

What causes RBCs to leave here and enter systemic circulation?

A

Spleen
At rest, 1/3 of RBCs are here
Exercise/stress -> adrenaline -> spleen contracts -> RBCs enter circulation. PCV can increase from 30-40% to 50-70% at maximum exercise

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9
Q

Where do the rostral and caudal maxillary sinus’ drain?

A

Middle meatus

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10
Q

Define a mare

A

A female horse 4 or more years old

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11
Q

What kind of breeder is a mare?

When is the breeding season?

A

A long day, seasonally polyoestrus breeder
(Most mares are in anoestrus over winter)
Increasing day length -> breeding season lasts from spring to late summer
A ‘transitional period’ of irregular cycling occurs at the start and end of the season

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12
Q

When does puberty occur in the mare?

A

Between 12 and 24 months

Cycling occurs for rest of life (although fertility may decline)

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13
Q

How long is the oestrus cycle in a horse?
How long does oestrus last?
When does dioestrus occur?

A

Cycle: 21 days
Oestrus: 4-6 days (ovulates in the last 25-48 hrs
Dioestrus: 16-17

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14
Q

Describe the oestrus cycle of a mare

A

Dioestrus: waves of follicles develop, reaching 25mm in size, then regress.
When hormonal conditions are correct, one follicle develops into a ‘dominant’ follicle -> produces oestrogens which induce oestrus
When it reaches >35mm -> ovulates
Oestrus ends within 24 hrs after ovulation
Ovulation site becomes corpus haemorrhagicum then corpus luteum (which produces progesterone)
The CL is refractory to effects of prostaglandins for 3-4 days after formation. After 15 days, endometrium releases prostaglandin -> luteolysis

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15
Q

What stimulates initial growth of follicles during dioestrus?

A

FSH

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16
Q

What stimulates oocyte and follicle maturation and ovulation during oestrus?

A

LH

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17
Q

What is the ‘transitional period’ during the reproductive cycle?

A

A period of change from anoestrus to regular cyclical activity
Lasts up to 6 weeks
Ovaries possess multiple small follicles 10-25mm diameter (‘bunch of grapes’)
Transitional follicles don’t ovulate and eventually regress
Mares show no sign of oestrus/behaviour
Mares mated now will not conceive (as there are no dominant follicles)
Eventually one follicle will develop properly and oestrus cycle will commence
Similar period happens when mares pass into anoestrus from oestrus (Autumn)

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18
Q

How can we manipulate oestrus using prostaglandins?

A

Induce luteolysis in CL
Oestrus will commence 3-5 days post injection
Side effects: transient colic, sweating, diarrhoea

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19
Q

How can we manipulate oestrus using progestagens?

A

Suppress oestrus
Withdrawal of treatment leads to rebound of ovarian activity; useful in shortening Spring transitional period
Intra-vaginal devices (PRID) sometimes used off-license

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20
Q

How can we manipulate oestrus using oestrogen?

A

Induce behavioural signs of oestrus (not true oestrus)

Only useful for maintaining ‘teaser mares’ for AI collection

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21
Q

How can we manipulate oestrus using chorionic gonadotrophin (eCG)?

A

If given during oestrus, will induce the dominant follicle (>35mm) to ovulate within 24 hours

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22
Q

How can we manipulate oestrus using Deslorelin (GnRH analogue)?

A

Hormone implant given sub-cut when follicle >30mm - should induce ovulation within 48hrs

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23
Q

How can we use light to manipulate oestrus?

A

Breeding season can be brought forward by using artificial light over winter
16hrs of light and 8 hrs dark from 2-4 weeks before Winter solstice
Light intensity important-should be able to read newspaper in darkest part of stable
Mares start to ovulate 8-10 weeks later

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24
Q

When should you serve a mare and why?

A

24-48 hours prior to ovulation
Oestrus behaviour ceases within 24hrs of ovulation-no longer receptive to stallion
Unfertilised oocyte viable for only 12 hrs post-ovulation
Spermatozoa viable for up to 48 hrs once in mare, take hours to reach oviduct
Mares served after ovulation have very poor conception rates

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25
How will a mare in oestrus look when being scanned?
Dominant follicle on one ovary Uterine oedema Soft oedematous cervix Oestrus: scan again 24-48 hrs later Not in oestrus: give prostaglandins and scan again 3-5 days later
26
What happens to the endometrium during oestrus?
Becomes increasingly oedematous | Oedema decreases in the 24 hrs before ovulation
27
How long after mating should you scan the mare? | What are you checking for?
12-48 hrs Has she ovulated (if not-mate again) Check only one ovulation (twins) Check for fluid in uterine lumen-post mating endometritis and treat accordingly
28
How is bacterial entry to the womb prevented?
Vulval seal Vestibular seal Cervical competence
29
How does poor perineal conformation lead to bacterial entry to the womb?
Poor perineal conformation prevents vulval and vestibular seals forming -> bacteria enters womb -> pneumovagina -> urovagina -> cervicitis Uterine contamination prevents implantation of conceptus
30
Describe a good perineal conformation
No more than 4cm of vulva above pelvic brim | No greater than 10 degree slope to the vulva
31
How can you treat perineal conformation problems?
Caslick's vulvoplasty Remove a very narrow strip of vulval mucosa and suture up vulval seal, leaving 3cm unopposed to allow for urination Sutures must be removed 5-10 days prior to parturition to prevent tears
32
How would you treat a persistent CL?
Give prostaglandins
33
What effects do granulosa cell tumours have on mares? How are they diagnosed? What is the treatment?
Cause either nymphomania, stallion-like behaviour or persistent anoestrus Diagnosed by scan and blood test for Anti-Mullerian hormone Surgery
34
Does endometritis affect conception?
No, but affects implantation and the inflammatory prostaglandins released may hasten luteolysis
35
What are the 3 types of endometritis?
Chronic infectious metritis Free fluid in lumen Mating-induced endometritis
36
Describe chronic infectious endometritis
Often caused by contamination of repro tract due to poor perineal conformation May be reduced uterine immune defences Agents include: E.coli, Pseudominas, Klebsiella, Strep. zooepidemicus, occasionally yeast/fungi
37
Describe endometritis where there is free-fluid in the lumen
Occurs as a result of uterine oedema during oestrus May be sterile initially but good culture medium for bacteria Could be due to delayed uterine clearance by incompetent mares (underlying motility disorder?)
38
Describe mating-induced endometritis
Mating contaminates repro tract with flora on stallions penis Semen is inflammatory in itself Transient inflammation is normal after mating/foaling/vaginal exam Should be cleared up within 12 hours Persists in some mares (abnormal uterine defences) -> embryonic loss, possibly chronic endometritis
39
How could you investigate endometritis?
Scan, especially post-service (needs treating if persistent fluid or fluid >1-2cm in depth) Uterine swab and smear (culture, cytology) Endometrial biopsy (histopath)
40
How can you treat endometritis?
``` Uterine lavage (saline) Oxytocin (repeated doses every few hours) Intrauterine antibiotics ```
41
How can you prevent endometritis?
Use of AI to minimise contamination
42
Why when treating endometritis, must you carry out treatment before day 5 of pregnancy?
The fertilised conceptus stays in the oviducts until about day 5 of pregnancy, after this it will be in the uterus. Therefore treatment of the uterus after day 5 will risk jeopardising the pregnancy
43
Describe chronic degenerative endometrial disease (endometriosis)
Progressive degeneration of endometrium and its replacement by fibrotic tissue Major cause of age-related infertility (esp Thoroughbreds) Begins about 11-12 yrs Pregnancy has a positive effect, and lessens progression Diagnosis: Histopath on endometrial biopsy No treatment
44
Why might a mare have cervical incompetence?
Congenital problems or from foaling injury
45
Uterine cysts look similar to pregnancies on a scan, how can you differentiate between them?
Re-scan the mare in 24-48 hrs; the cyst will remain static in size and shape whereas the cenceptus will grow and will be motile up to day 16
46
Do uterine cysts cause fertility problems?
Rarely, unless very large
47
How would you perform a pre-breeding disease clearance test?
Clitoral swab for contagious equine metritis, send off to lab
48
What is the gestation period of a horse?
340 days Overdue foals seldom cause a problem Prematurity -> neonatal disease
49
Where does fertilisation occur?
Ampulla of oviduct | Embryo remains here for 5 days then it enters the uterus
50
When does the embryo migrate around the uterus and why?
Between day 5 (enters uterus) and 15/16 | Essential for maternal recognition of pregnancy and prevention of prostaglandin release by endometrium
51
When does the embryo position itself in the uterus and where?
Day 15-16, usually at the base of a horn
52
When does placental attachment begin during pregnancy? | What else happens then?
Day 36 | Endometrial cup production and attachment
53
When does the foetus grow into the uterine body?
After 70-80 days | Found mostly in the body until 6-7 months, after which it is so large that it occupies part of the horn again
54
How is pregnancy maintained?
CL produces progesterone
55
When do endometrial cups start secreting eCG?
From day 35 | They maintain pregnancy for the first 5 months
56
What does eCG (equine chorionic gonadotropin) do during pregnancy?
Maintains primary CL and encourages secondary CL formation
57
When do endometrial cups degenerate during pregnancy?
Around day 70, gone by day 150
58
How are the first 5 months of pregnancy maintained?
Endometrial cups secrete eCG -> maintains primary CL and encourages formation of secondary CL
59
After about day 200 of pregnancy, all CLs have degenerated, so how is pregnancy maintained?
Foetal-placental progesterone production (acts locally)
60
When do foetal gonads start producing oestrogens during pregnancy?
From day 60 onwards
61
Abortions must be carried out by when if the mare is to be mated again in the same breeding season? Why?
Before day 35, as this is when endometrial cups develop. These remain even if the foal has died. The mare will not come into oestrus whilst the cups are present.
62
How can you diagnose equine pregnancy?
``` Failure of mare to return to oestrus Lab tests (serum, measure eCG from days 45-90, or oestrone sulphate from day 120 onwards) (urine-oestrone sulphate from day 150) Manual rectal exam (usually done at 6 weeks, can ballot foetus at day 120) Rectal ultrasound (can be done from about 10 days after mating, although embryonic death and twins can occur after this) ```
63
When during pregnancy are early embryonic death rates highest?
In first 14 days
64
From when can you only image parts of the foetus, not the whole thing? (scanning)
6 weeks
65
When are PD scans usually carried out? (3)
15-16 days post-mating - check for pregnancy or return to oestrus - check for twins (can reduce whilst embryos are motile and can be separated, and before endometrial cups have developed) 24-26 days post-mating - heartbeat visible - can still reduce twins before cups have established ``` 6 weeks (optional) -reassess (embryonic death less likely) ```
66
On a rectal ultrasound, how big will the conceptus be at 14 days, 16 days, 20 days, 25 days and 65 days?
``` 14 days= 1cm 16 days= 1.5cm 20 days= 2cm 25 days= 3cm 65 days= 10cm ```
67
From when can a trans-abdominal scan be performed?
6 months onwards
68
How do you classify foetal death during pregnancy?
From fertilisation to day 40: early embryonic death Day 40-300: abortion Day 300 onwards: stillbirth
69
Give some causes of failure of pregnancy
``` Early embryonic death Viral (EHV-equine herpes virus 1, EVA-equine viral arteritis) Bacterial Fungal Twins Maternal stress/illness Foetal abnormalities Umbilical torsion Idiopathic ```
70
Give some causes of early embryonic death
Congenital abnomalities Breeding on foal heat Uterine environment problems (fibrosis, endometritis)
71
How may you reduce the risk of equine herpes virus in pregnant mares?
Vaccinate at 5, 7 and 9 months of pregnancy | May reduce risk of disease but doesn't give full immunity
72
How can you diagnose equine herpes virus in pregnant mares?
PCR of nasopharyngeal swabs for horses showing respiratory signs PCR of aborted material
73
When does abortion from equine herpes virus 1 occur?
Late term (>5 months), 1-3 months post-infection
74
How does equine viral arteritis (EVA) affect stallions and mares?
Stallions: become persistent infected shedders Mares: abort then recover Notifiable Vaccine available
75
Which bacteria usually cause bacterial abortion? | How do they cause abortion?
Strep species, E.coli, Staph species Occasionally Salmonella, Leptosporosis Causes: ascending infection from cervix, haematogenous spread, introduction of bacteria at breeding (from stallion's penis)
76
Although fungal infection is a rare cause of abortion, which fungal species is usually the cause?
Aspergillus spp
77
Why does a twin pregnancy lead to failure of pregnancy?
Mares are not designed to carry more than 1 foal- placenta needs to contact up to 70% of available uterus for adequate nutrition of foetus Twins compete with each other for attachment space (nutrition). Often one twin runs out of space and dies. The other twin eventually is deprived of space by the remnants of the dead twin and is aborted.
78
Which is more likely to result in one twin being born: Both twins in same horn Twins in opposite horns Why?
Both twins in same horn, as one twin may die early on whilst it is still small. If in opposite horns, twins are more likely to abort as they'll both get to a reasonable size before competing with each other
79
What percentage of twin pregnancies results in 2 live foals?
2 live: 1%
80
Of twin pregnancies, what percentage results in a live foal?
63%
81
What are some signs of abortion?
Vaginal discharge Running milk Colic/foaling signs May be no signs at all
82
How can you investigate abortion?
Send whole foal carcass and placenta to pathologist If not possible: Examine placenta and cord External exam of foal: weight, crown-rump length Internal exam Sample chorion, thymus, liver, lung, spleen Samples from mare rarely useful
83
How do you induce abortion before 3 months?
Prostaglandin infection, abortion will occur 5-8 days later | If endometrial cups present, mare will not return to oestrus this breeding season
84
How do you induce abortion after 3 months?
Repeated prostaglandin injections (twice daily between days 80-150 -> abortion 2-5 days later) Dilation of cervix and uterine lavage Trans-abdominal injection of potassium chloride into foetal heart? Dislocation of foetal neck per rectum? Considerable risk in attempting termination of pregnancies after 100 days
85
How do you induce foaling?
Inject 1-2ml oxytoxin every 15-20 mins until delivery starts (may only need 1 dose) Mare must be close to foaling anyway
86
What are the risks with inducing foaling?
Uterine rupture Dystocia Foal immaturity (matures in last 1% of pregnancy) Retained membranes Avoid unless absolutely necessary
87
What kind of placenta does a horse have?
Diffuse, epithelio-chorial
88
Give some risk factors for neonatal disease
Mare: placentitis, placental insufficiency, maternal illness, early lactation, poor colostral production Foal: prematurity, failure of passive transfer Dystocia Premature placental separation
89
How long does it take a newborn foal to adapt to the external environment? How one does it take it to stand and suck?
24-48 hours | Usually stands within 1 hour, sucks within 2
90
What is the difference between prematurity and dysmaturity?
Prematurity: a foal born before 320 days gestation that displays immature physical characteristics Dysmaturity: a full-term foal that displays immature physical characteristics
91
Give some characteristics of a premature/dysmature foal?
``` Low birth rate Short, silky hair coat Floppy ears Domed head Weakness, prolonged time to stand Flexor tendon laxity Incomplete ossification of tarsal and carpal bones Severe cases: multiplayer organ dysfunction (eg respiratory depression) ```
92
By when do foals have adult levels of IgG?
4 months old
93
When is the crossover between maternal and foal IgG?
8-9 weeks old | IgG= 400mg/dl
94
What is the half life of maternal IgG?
20-23 days | Declines by 1-2 months
95
How are colostral antibodies absorbed?
Specialist enterocytes absorb the IgG by pinocytosis These cells have a lifespan of max 24 hours Maximum absorption occurs within 8 hours of life
96
How much colostrum must a foal have?
1 litre of colostrum within first 6 hours of life
97
Give some predisposing factors for failure of passive transfer
Loss of colostrum via premature lactation (eg due to premature placental separation) Inadequate colostrum (IgG/volume) production Failure to ingest adequate volume of colostrum Failure to absorb colostrum
98
When is the best time to test passive transfer? | How?
18-24 hours ZST (zinc sulphate turbidity test) ELISA Colostrum specific gravity can be tested pre-suck
99
What value of IgG indicates normal transfer of maternal antibodies?
>8g/l
100
How do you treat failure of passive transfer?
If >12-24 hours, give foal plasma (from mare or commercial)
101
What are the consequences of failure of passive transfer?
Immediate-septicaemia | Rotaviral infections, joint sepsis, respiratory disease (1-4 months old)
102
By when should a foal develop a suck reflex?
Within 20 minutes
103
What is the body temp of a horse?
36.5- 38.5 (don't show very high temperatures unless very unwell)
104
What is the body temp of a foal?
37.2-38.9 degrees (reflects environmental temp)
105
What is the heart rate of a foal?
Birth: 40-80 bpm | First week: 60-190 bpm
106
What is the heart rate of a horse?
27-40 bpm
107
What is the resp rate of an adult horse?
12-16 brpm
108
What is the resp rate of a foal?
Newborn: 45-60 brpm (no nostril flaring or exaggerated rib movement) 7 days of age: 35-50 brpm
109
By when should a foal pass meconium?
Within 24 hours
110
By when should a foal first urinate?
Dilute and large volumes first passed by 6 hours (colts) or 10 hours (fillies)
111
What is the average weight of a newborn foal?
45-55kg
112
What is the average weight gain of a new born foal?
0.5-1.5 kg/day
113
How much of its mothers milk should a newborn foal consume a day?
20-28% bodyweight | Feed every 2 hours
114
What partial pressure of oxygen indicates cyanosis in foals?
PaO2
115
Give some signs of sepsis in the mucous membranes of a foal
Congestion, petechiae | Brick red mucous membranes
116
When doing a physical exam on a foal, where should you pay particular attention to?
Umbilicus Joints Mucous membranes Auscultation
117
How can you identify sepsis in a foal?
``` Blood culture (3 days for results, changes in foal can happen within hours) Sepsis score (neutrophil numbers, fibrinogen concentration, blood glucose, clinical exam, history) ```
118
How can you identify umbilical infection in a foal?
Ultrasound-look at umbilical vessels Enlarged umbilicus Drainage of pus Pain on palpation
119
How can you diagnose pneumonia in a foal?
Radiography, blood gas analysis
120
How can you diagnose osteomyelitis/arthritis in a foal?
Synovial fluid analysis, radiography
121
Give an NSAID suitable for septicaemic foals
Flunixin 0.5-1mg/kg bid
122
What is oliguria? | What could you give to a foal with oliguria?
Production of abnormally small amounts of urine | Diuretics if persistent (furosemide-loop or mannitol-osmotic)
123
How often should you feed a sick foal?
Every 2 hours
124
Which antibiotics can you use in foals?
Aminoglycosides (care in young foals- nephrotoxicity) Penicillins and other beta-lactams Ceftiofur (high doses eg 5mg/kg) Cefquinome 1mg/kg
125
How can you provide respiratory support in a newborn foal?
Move it from lateral to sternal recumbency (improves resp function) Intranasal oxygen Mechanical ventilation Drugs (bronchodilators- B2 agonists, central stimulants)
126
Describe a sick foal
Weak, depressed, lack of suck reflex
127
What is the most important differential in a sick foal?
Neonatal septicaemia | Risk factors: FPT, hygiene, stress, management, disease
128
Which common pathogens can cause septicaemia in foals?
E.coli, Actinobacillus, Salmonella spp, Proteus, Klebsiella (all gram negative) Beta-haemolytic streptococcus, Staphyocloccus, clodtridia
129
How do organisms enter the foal to cause septicaemia?
Openings (umbilicus?) Open gut Inhalation In utero (mare placentitis)
130
What are the clinical signs of foal septicaemia?
Foal is off suck and lethargic Increase resp rate and effort Acute severe lameness Discharge or swelling of umbilicus Congested, dark mucous membranes or severe petechial haemeorrhages Hypopyon (pus in anterior chamber of eye) Diarrhoea Meningitis Fever not consistent (shock= low temp, SARS= high temp)
131
What is SARS?
Severe acute respiratory syndrome
132
Describe the physiology of septic shock (SIRS- systemic inflammatory response syndrome)
Vasoactive inflammatory mediators -> vasodilation Increased metabolic rate and oxygen consumption CO initially increased (hyperdynamic phase) Microvascular permeability -> volume maldistribution Increased CO can no longer be maintained (hypodynamic phase)
133
What does septic shock result in in foals?
Multiple organ failure CNS depression Renal failure Autonomic exhaustion and decompensation of circulation
134
Give some differential diagnoses for a foal with respiratory signs
``` Neonatal septicaemia Viral pneumonia Meconium aspiration Aspiration pneumonia Pneumothorax Respiratory distress syndrome Pulmonary hypertension Central respiratory depression ```
135
What is CID/SDID?
Failure to produce functional B and T lymphocytes Autosomal recessive Arab breeds Normal at birth, disease begins at 1-2 months old Lethal
136
How do you diagnose CID/SCID?
Clinical signs | Persistent lymphopenia
137
What is PAS?
Perinatal asphyxia syndrome
138
Describe PAS
Dummy foals HIE (hypoxic ischaemic encephalopathy) Ischaemia, oedema and reperfusion injury to brain, kidneys, intestines and other organs due to lack of oxygen Caused by in utero hypoxia or interruption of oxygen supply during birth May not be apparent until foal is 12-24 hours old Central respiratory depression
139
Give the symptoms of mild, moderate and severe PAS
Mild: unable to attach to mare, poor suck reflex Moderate: aimless wandering, abnormal phonation ('barkers'), blind Severe: seizures, coma
140
How can you control seizures in foals with PAS?
Diazepam, phenobarbital
141
What can be given to foal with PAS that have cerebral oedema?
DMSO (dimethyl-sulfoxide) | Has anti inflammatory properties, traps free radicals
142
Are ruptured bladders more common in male or female foals?
Male due to longer urethra
143
Describe the aetiology of a ruptured bladder in a foal?
Usually excessive pressure during parturition on a distended bladder Congenital defect also possible, due to dorsal site where there is a change in the muscle of the bladder wall
144
Describe the presentation of a foal with a ruptured bladder
Signs normally present within first 2-3 days of life Dysuria (painful urination) esp stranguria (frequent attempts to urinate with only small amounts passed) Depression and abdominal distension after 2 days
145
How do you diagnose a ruptured bladder in a foal?
Post-renal azotaemia with hyponatraemia (low sodium), hypochloraemia (low chloride ions) and hyperkalaemia (high potassium) Ultrasound (urine in abdomen) May see calcium carbonate crystals in peritoneal fluid
146
Why do newborn foals have proteinuria?
Absorb small molecular weight proteins from colostrum
147
How do you manage a ruptured bladder in a foal?
Correct metabolic acidosis and electrolyte changes with IV fluids Hyperkalaemia may induce arrythmias -> give 0.9% saline with 5% glucose Resp distress, atelectasis etc should be corrected with oxygen therapy, ventilation and reducing abdominal fluid Slowly drain peritoneal fluid prior to surgery (it removing urachus)
148
How does a foal with colic present?
Quiet, will lie down and curl up (like a croissant)
149
What are some differential diagnoses for a foal with colic?
``` Meconium impaction Ruptured bladder/uroperitoneum Overfeeding/ lactose intolerance Distension from diarrhoea Gastric ulcers SI/ LI obstruction Congenital abnormalities ```
150
Newborn foals have 30-40% higher what than an adult?
Creatinine
151
Describe neonatal isoerythrolysis
Aa and Qa negative mares mated to positive stallions Foal inherits RBC antigens from stallion Exposure of the mare to these antigens causes her to produce alloantibodies to the foals RBCs At birth, the foal ingests later numbers of RBC antibodies in colostrum -> haemolytic anaemia
152
How can you diagnose neonatal isoerythrolysis?
Coombs test to detect antibodies on RBCS
153
How can you prevent neonatal isoerythrolysis?
Blood type both parents before mating | Can withhold colostrum or use jaundiced foal agglutination (JFA) test to detect antibodies against foal RBC's
154
What is the treatment for neonatal isoerythrolysis?
``` Blood transfusion (if PCV 12-15% or less) Donors must be Qa or Aa negative, or washed mare RBCs Supportive care (antibiotics, anti-ulcer meds, monitor fluids, glucose, nursing) ```
155
Foal heat diarrhoea affects foals of what age? Why does it occur? How does it present?
5-12 days Changes in bacterial flora in foal Alteration in milk composition relating to hormonal changes in mare (oestrus) Mild, self-limiting diarrhoea No treatments, or can use probiotics or intestinal protectants
156
Describe clostridial diarrhoea
Severe peracute frequently fatal Necrotising foul-smelling faeces Seen in individual septicaemic foals and as outbreaks Cl difficile and Cl perfringens most common (normal Gi inhabitants) Severe gas distension and colic Contagious-isolate
157
How do you diagnose clostridial diarrhoea in foals?
Culture- normal flora so interpretation difficult ELISA or PCR (for toxins) Gas in or on the mucosa in ultrasound
158
How do you treat clostridial diarrhoea?
Metronidazole, penicillin
159
Describe cryptosporidium infection in foals
``` No intermediate hosts Faeco-oral infection Attach to brush border Incubation 3-7 days Diagnosis: flotation of faecal Oocytes or direct FA Treatment: supportive therapy Prevention: good hygiene and management ```
160
Describe rotavirus infection in foals
1-4 weeks of age Highly infectious (outbreaks) Diarrhoea Diagnosis: ELISA, electron microscopy Treatment: passive immunisation, supportive therapy Prevention: phenolic disinfectants,passive immunisation, vaccination of pregnant mares?
161
What causes equine strangles?
Streptococcus equi
162
Describe Rhodococcus equi
``` Excreted in dams faeces, builds up on pasture in warm, dry conditions, ingested, colonises WBCs, abscessation Enteric infection (persistent diarrhoea, fever) Intra-abdominal abscess (fever, colic) ```
163
What causes equine proliferative enteropathy (EPE)?
Lawsonia intracellularis
164
What are the effects of equine proliferative enteropathy (EPE)? How old are affected foals? How do they get it?
Weight loss, oedema, lethargy, depression, weakness, diarrhoea, mild colic 3-11 months of age Infection from faeces (equine or other species)
165
How do you diagnose equine proliferative enteropathy (EPE)?
Ultrasound Hypoproteinaemia PCR of faeces and serology
166
How do you treat equine proliferative enteropathy (EPE)?
Antimicrobials eh erythromycin, rifampin, Oxytetracycline
167
Give some mechanisms for weight loss in a horse
Reduced intake: inappropriate feeding, competition for feed, dental disorders, dysphagia, unable to obtain feed Reduced digestion or absorption of nutrients: dental disorders, malabsorption syndrome, liver disease Increased losses: protein-losing enteropathy Increased requirements: pregnancy, lactation, sepsis, neoplasia, other systemic disease
168
Give some common causes of weight loss
Dental disorders, parasitism, inadequate diet, PPID (Cushings disease), liver disease, malabsorption and protein-losing enteropathy, chronic diarrhoea, abdominal abscess, renal disease, cardiac disease. Chronic thoracic disease, non-GI neoplasia, equine grass sickness
169
Why are enzyme deficiencies not a problem in horses?
Bacteria in the hind-gut are able to adapt to increased substances eg lactose that would increase in the absence of enzymes
170
What % of a horses BWT should it be eating in bulk?
Between 2 and 2.5% BW in roughage
171
What is the difference between chronic and recurrent colic?
Chronic: colic signs of variable intensity lasting 48 hours or more Recurrent: shorter period of colic pain which recur at variable intervals
172
What is 'colic?'
Acute abdominal pain Only a symptom Most commonly related to GI tract
173
Give the causes of recurrent colic
Anything that pulls on the mesentery Non-intestinal Gastrointestinal: mesenteric traction, motility disorders, inflammatory, intermittent partial/complete obstruction
174
What % DM is hay, haylage and grass?
Hay: 85% Haylage: 65% Grass: 45%
175
Crib-biting increases the likelihood of which type of colic?
Gas-type colic
176
What should you check when investigating chronic GIT disease?
``` History-weight loss? Previous colic? Rectal exam Diet Teeth Worming history/faecal test Possible feed competition Next check serum proteins, the perform peritoneal fluid analysis ```
177
Tapeworms can cause colic in which location?
Ileo-caecal junction
178
How does chronic inflammatory disease affect globulins?
Causes hyperglobulinaemia
179
Give some causes of hyperfibrinogenaemia
Infection Inflammation Neoplasia
180
How can you investigate weight loss?
Oral glucose absorption test (SI): starve overnight, give 1gm/kg in a 20% soliton administered by nasogastric tube, measure absorption into blood Rectal biopsy Duodenal biopsy
181
Describe the results of an oral glucose absorption test
Normal: >85% increase in blood glucose concentration at 2 hours Partial: 15-85% increases at 2 hours (SI or LI disease, or normal) Complete:
182
From where should you take a rectal biopsy?
20-30cm inside rectum at 4 or 8 o clock | Take a small piece of mucosa
183
Where would you scan to view the stomach on an ultrasound?
8th-13th intercostal space, left side of abdomen
184
How do infiltrative bowel diseases cause weight loss?
Presence of inflammatory cells in intestinal wall -> malabsorption and protein-loss
185
How do you treat infiltrative bowel diseases?
Prednisolone Dexamethasone Anthelmintics
186
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
186
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
187
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
188
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
189
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
190
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
191
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
192
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
193
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
194
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
195
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
196
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
197
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
198
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
199
What percentage of colic cases require surgery?
7%
200
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
201
Which sedative should you give to a horse with violently painful colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
202
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
203
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
204
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
205
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
206
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
207
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
208
What is the normal packed cell volume of a horse?
35-45%
209
What is the normal value for systemic total protein?
60-70g/L
210
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
211
What is the most common cause of colic in the foal?
Meconium impaction
212
What is the medical term for equine grass sickness?
Equine dysautonomia
213
What is the suspected cause of equine grass sickness? | What are the clinical signs?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
214
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
215
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
216
What is the tidal volume of a horse at rest?
5L
217
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
218
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
219
How do you work out minute ventilation?
Tidal volume x resp rate
220
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
221
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? (unilateral=lesion rostral to nasal septum) Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
222
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
223
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
224
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
225
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
226
Is 'roaring' heard during inspiration or expiration?
Inspiration
227
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
228
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
229
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
230
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
231
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
232
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
233
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
234
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
235
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
236
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
237
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
238
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
239
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
240
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
241
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
242
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
243
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
244
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
245
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
246
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
247
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
248
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
249
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
250
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
251
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
252
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
253
How does drainage of sinuses occur?
Gravity and mucociliary action
254
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
255
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
256
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
257
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
258
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
259
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
260
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
261
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
262
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
263
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
264
How do you treat a paranasal sinus cyst?
Surgical removal
265
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
266
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
267
What separates the nasopharynx from the oropharynx?
Soft palate
268
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
269
How does the pharynx retain stability?
Coordinated neuromuscular function
270
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
271
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
272
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
273
Which muscle is the principle abductor of the glottis? | When does it abduct the glottis?
Cricoarytenoideus dorsalis | Opens glottis during exercise
274
Which muscle is the principle adductor of the glottis? | When does it close the glottis?
Cricoarytenoidalis lateralis | Closes glottis during swallowing
275
When does the glottis open and close?
Open: exercise Close: swallowing
276
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
277
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
278
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
279
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
280
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
281
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
282
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
283
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
284
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
285
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
286
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
287
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
288
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
289
How would you identify a foal with cleft palate?
Milk at nostril
290
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
291
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
292
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
293
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
294
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
295
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
296
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
297
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
298
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
299
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
300
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
301
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
302
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
303
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
304
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
305
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
306
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
307
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
308
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
309
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
310
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
311
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
312
How do you diagnose gutteral pouch mycosis?
Endoscopy
313
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
314
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
315
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
316
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
317
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
318
Describe gutteral pouch tympany
Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy Tx: fenestration of membrane separating the two pouches to allow air to move into the non-affected pouch and leave through pharynx
319
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
320
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
321
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
322
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
323
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
324
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
325
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
326
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
327
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
328
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
329
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
330
How big are pinworms?
2-13mm
331
What is the proper name for pinworm?
Oxyuris equi
332
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
333
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
334
What does atopy mean?
Hyperallergic
335
How do you diagnose atopy?
Intradermal skin testing
336
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
337
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
338
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
339
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
340
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
341
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
342
Give an antifungal used to treat ringworm?
Miconazole
343
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
344
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
345
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
346
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
347
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
348
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
349
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
350
How do you treat a melanoma?
Surgical excision, immunotherapy
351
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
352
Where are mast cell rumours found?
Head Solitary Males
353
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
354
What is the name of the equine roundworm?
Parascaris equorum
356
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
357
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
358
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
359
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
360
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
361
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
362
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
363
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
364
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
365
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
366
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
367
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
368
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
369
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
370
What percentage of colic cases require surgery?
7%
371
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
372
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
373
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
374
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
375
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
376
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
377
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
378
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
379
What is the normal packed cell volume of a horse?
35-45%
380
What is the normal value for systemic total protein?
60-70g/L
381
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
382
What is the most common cause of colic in the foal?
Meconium impaction
383
What is the medical term for equine grass sickness?
Equine dysautonomia
384
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
385
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
386
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
387
What is the tidal volume of a horse at rest?
5L
388
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
389
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
390
How do you work out minute ventilation?
Tidal volume x resp rate
391
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
392
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
393
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
394
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
395
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
396
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
397
Is 'roaring' heard during inspiration or expiration?
Inspiration
398
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
399
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
400
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
401
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
402
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
403
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
404
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
405
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
406
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
407
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
408
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
409
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
410
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
411
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
412
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
413
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
414
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
415
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
416
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
417
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
418
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
419
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
420
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
421
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
422
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
423
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
424
How does drainage of sinuses occur?
Gravity and mucociliary action
425
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
426
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
427
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
428
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
429
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
430
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
431
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
432
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
433
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
434
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
435
How do you treat a paranasal sinus cyst?
Surgical removal
436
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
437
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
438
What separates the nasopharynx from the oropharynx?
Soft palate
439
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
440
How does the pharynx retain stability?
Coordinated neuromuscular function
441
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
442
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
443
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
444
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
445
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
446
When does the glottis open and close?
Open: exercise Close: swallowing
447
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
448
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
449
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
450
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
451
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
452
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
453
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
454
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
455
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
456
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
457
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
458
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
459
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
460
How would you identify a foal with cleft palate?
Milk at nostril
461
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
462
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
463
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
464
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
465
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
466
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
467
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
468
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
469
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
470
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
471
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
472
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
473
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
474
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
475
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
476
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
477
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
478
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
479
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
480
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
481
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
482
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
483
How do you diagnose gutteral pouch mycosis?
Endoscopy
484
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
485
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
486
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
487
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
488
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
489
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
490
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
491
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
492
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
493
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
494
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
495
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
496
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
497
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
498
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
499
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
500
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
501
How big are pinworms?
2-13mm
502
What is the proper name for pinworm?
Oxyuris equi
503
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
504
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
505
What does atopy mean?
Hyperallergic
506
How do you diagnose atopy?
Intradermal skin testing
507
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
508
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
509
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
510
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
511
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
512
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
513
Give an antifungal used to treat ringworm?
Miconazole
514
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
515
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
516
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
517
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
518
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
519
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
520
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
521
How do you treat a melanoma?
Surgical excision, immunotherapy
522
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
523
Where are mast cell rumours found?
Head Solitary Males
524
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
525
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
526
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
527
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
528
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
529
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
530
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
531
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
532
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
533
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
534
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
535
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
536
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
537
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
538
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
539
What percentage of colic cases require surgery?
7%
540
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
541
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
542
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
543
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
544
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
545
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
546
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
547
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
548
What is the normal packed cell volume of a horse?
35-45%
549
What is the normal value for systemic total protein?
60-70g/L
550
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
551
What is the most common cause of colic in the foal?
Meconium impaction
552
What is the medical term for equine grass sickness?
Equine dysautonomia
553
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
554
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
555
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
556
What is the tidal volume of a horse at rest?
5L
557
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
558
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
559
How do you work out minute ventilation?
Tidal volume x resp rate
560
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
561
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
562
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
563
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
564
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
565
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
566
Is 'roaring' heard during inspiration or expiration?
Inspiration
567
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
568
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
569
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
570
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
571
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
572
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
573
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
574
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
575
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
576
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
577
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
578
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
579
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
580
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
581
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
582
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
583
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
584
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
585
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
586
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
587
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
588
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
589
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
590
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
591
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
592
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
593
How does drainage of sinuses occur?
Gravity and mucociliary action
594
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
595
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
596
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
597
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
598
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
599
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
600
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
601
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
602
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
603
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
604
How do you treat a paranasal sinus cyst?
Surgical removal
605
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
606
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
607
What separates the nasopharynx from the oropharynx?
Soft palate
608
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
609
How does the pharynx retain stability?
Coordinated neuromuscular function
610
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
611
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
612
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
613
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
614
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
615
When does the glottis open and close?
Open: exercise Close: swallowing
616
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
617
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
618
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
619
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
620
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
621
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
622
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
623
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
624
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
625
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
626
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
627
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
628
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
629
How would you identify a foal with cleft palate?
Milk at nostril
630
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
631
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
632
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
633
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
634
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
635
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
636
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
637
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
638
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
639
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
640
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
641
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
642
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
643
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
644
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
645
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
646
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
647
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
648
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
649
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
650
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
651
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
652
How do you diagnose gutteral pouch mycosis?
Endoscopy
653
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
654
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
655
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
656
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
657
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
658
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
659
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
660
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
661
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
662
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
663
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
664
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
665
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
666
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
667
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
668
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
669
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
670
How big are pinworms?
2-13mm
671
What is the proper name for pinworm?
Oxyuris equi
672
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
673
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
674
What does atopy mean?
Hyperallergic
675
How do you diagnose atopy?
Intradermal skin testing
676
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
677
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
678
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
679
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
680
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
681
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
682
Give an antifungal used to treat ringworm?
Miconazole
683
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
684
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
685
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
686
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
687
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
688
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
689
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
690
How do you treat a melanoma?
Surgical excision, immunotherapy
691
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
692
Where are mast cell rumours found?
Head Solitary Males
693
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
694
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
695
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
696
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
697
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
698
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
699
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
700
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
701
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
702
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
703
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
704
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
705
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
706
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
707
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
708
What percentage of colic cases require surgery?
7%
709
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
710
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
711
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
712
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
713
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
714
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
715
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
716
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
717
What is the normal packed cell volume of a horse?
35-45%
718
What is the normal value for systemic total protein?
60-70g/L
719
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
720
What is the most common cause of colic in the foal?
Meconium impaction
721
What is the medical term for equine grass sickness?
Equine dysautonomia
722
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
723
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
724
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
725
What is the tidal volume of a horse at rest?
5L
726
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
727
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
728
How do you work out minute ventilation?
Tidal volume x resp rate
729
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
730
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
731
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
732
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
733
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
734
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
735
Is 'roaring' heard during inspiration or expiration?
Inspiration
736
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
737
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
738
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
739
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
740
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
741
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
742
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
743
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
744
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
745
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
746
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
747
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
748
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
749
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
750
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
751
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
752
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
753
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
754
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
755
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
756
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
757
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
758
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
759
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
760
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
761
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
762
How does drainage of sinuses occur?
Gravity and mucociliary action
763
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
764
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
765
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
766
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
767
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
768
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
769
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
770
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
771
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
772
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
773
How do you treat a paranasal sinus cyst?
Surgical removal
774
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
775
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
776
What separates the nasopharynx from the oropharynx?
Soft palate
777
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
778
How does the pharynx retain stability?
Coordinated neuromuscular function
779
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
780
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
781
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
782
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
783
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
784
When does the glottis open and close?
Open: exercise Close: swallowing
785
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
786
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
787
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
788
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
789
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
790
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
791
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
792
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
793
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
794
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
795
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
796
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
797
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
798
How would you identify a foal with cleft palate?
Milk at nostril
799
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
800
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
801
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
802
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
803
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
804
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
805
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
806
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
807
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
808
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
809
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
810
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
811
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
812
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
813
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
814
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
815
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
816
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
817
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
818
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
819
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
820
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
821
How do you diagnose gutteral pouch mycosis?
Endoscopy
822
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
823
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
824
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
825
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
826
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
827
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
828
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
829
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
830
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
831
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
832
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
833
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
834
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
835
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
836
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
837
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
838
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
839
How big are pinworms?
2-13mm
840
What is the proper name for pinworm?
Oxyuris equi
841
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
842
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
843
What does atopy mean?
Hyperallergic
844
How do you diagnose atopy?
Intradermal skin testing
845
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
846
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
847
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
848
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
849
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
850
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
851
Give an antifungal used to treat ringworm?
Miconazole
852
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
853
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
854
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
855
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
856
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
857
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
858
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
859
How do you treat a melanoma?
Surgical excision, immunotherapy
860
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
861
Where are mast cell rumours found?
Head Solitary Males
862
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
863
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
864
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
865
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
866
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
867
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
868
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
869
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
870
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
871
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
872
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
873
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
874
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
875
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
876
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
877
What percentage of colic cases require surgery?
7%
878
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
879
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
880
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
881
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
882
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
883
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
884
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
885
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
886
What is the normal packed cell volume of a horse?
35-45%
887
What is the normal value for systemic total protein?
60-70g/L
888
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
889
What is the most common cause of colic in the foal?
Meconium impaction
890
What is the medical term for equine grass sickness?
Equine dysautonomia
891
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
892
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
893
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
894
What is the tidal volume of a horse at rest?
5L
895
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
896
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
897
How do you work out minute ventilation?
Tidal volume x resp rate
898
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
899
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
900
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
901
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
902
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
903
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
904
Is 'roaring' heard during inspiration or expiration?
Inspiration
905
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
906
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
907
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
908
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
909
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
910
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
911
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
912
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
913
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
914
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
915
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
916
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
917
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
918
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
919
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
920
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
921
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
922
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
923
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
924
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
925
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
926
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
927
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
928
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
929
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
930
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
931
How does drainage of sinuses occur?
Gravity and mucociliary action
932
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
933
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
934
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
935
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
936
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
937
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
938
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
939
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
940
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
941
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
942
How do you treat a paranasal sinus cyst?
Surgical removal
943
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
944
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
945
What separates the nasopharynx from the oropharynx?
Soft palate
946
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
947
How does the pharynx retain stability?
Coordinated neuromuscular function
948
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
949
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
950
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
951
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
952
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
953
When does the glottis open and close?
Open: exercise Close: swallowing
954
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
955
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
956
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
957
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
958
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
959
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
960
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
961
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
962
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
963
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
964
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
965
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
966
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
967
How would you identify a foal with cleft palate?
Milk at nostril
968
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
969
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
970
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
971
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
972
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
973
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
974
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
975
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
976
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
977
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
978
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
979
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
980
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
981
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
982
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
983
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
984
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
985
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
986
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
987
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
988
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
989
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
990
How do you diagnose gutteral pouch mycosis?
Endoscopy
991
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
992
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
993
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
994
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
995
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
996
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
997
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
998
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
999
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1000
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1001
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1002
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1003
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1004
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1005
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1006
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1007
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1008
How big are pinworms?
2-13mm
1009
What is the proper name for pinworm?
Oxyuris equi
1010
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1011
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1012
What does atopy mean?
Hyperallergic
1013
How do you diagnose atopy?
Intradermal skin testing
1014
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1015
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1016
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1017
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1018
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1019
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1020
Give an antifungal used to treat ringworm?
Miconazole
1021
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1022
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1023
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1024
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1025
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1026
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1027
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1028
How do you treat a melanoma?
Surgical excision, immunotherapy
1029
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1030
Where are mast cell rumours found?
Head Solitary Males
1031
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1032
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1033
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1034
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1035
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1036
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1037
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1038
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1039
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1040
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1041
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1042
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1043
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1044
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1045
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1046
What percentage of colic cases require surgery?
7%
1047
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1048
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1049
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1050
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1051
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1052
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1053
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1054
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1055
What is the normal packed cell volume of a horse?
35-45%
1056
What is the normal value for systemic total protein?
60-70g/L
1057
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1058
What is the most common cause of colic in the foal?
Meconium impaction
1059
What is the medical term for equine grass sickness?
Equine dysautonomia
1060
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1061
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1062
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1063
What is the tidal volume of a horse at rest?
5L
1064
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1065
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1066
How do you work out minute ventilation?
Tidal volume x resp rate
1067
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1068
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1069
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1070
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1071
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1072
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1073
Is 'roaring' heard during inspiration or expiration?
Inspiration
1074
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1075
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1076
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1077
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1078
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1079
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1080
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1081
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1082
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1083
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1084
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1085
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1086
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1087
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1088
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1089
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1090
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1091
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1092
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1093
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1094
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1095
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1096
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1097
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1098
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1099
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1100
How does drainage of sinuses occur?
Gravity and mucociliary action
1101
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1102
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1103
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1104
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1105
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1106
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1107
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1108
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1109
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1110
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1111
How do you treat a paranasal sinus cyst?
Surgical removal
1112
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1113
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1114
What separates the nasopharynx from the oropharynx?
Soft palate
1115
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1116
How does the pharynx retain stability?
Coordinated neuromuscular function
1117
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1118
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1119
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1120
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1121
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1122
When does the glottis open and close?
Open: exercise Close: swallowing
1123
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1124
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1125
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1126
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1127
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1128
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1129
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1130
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1131
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1132
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1133
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1134
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1135
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1136
How would you identify a foal with cleft palate?
Milk at nostril
1137
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1138
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1139
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1140
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1141
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1142
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1143
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1144
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1145
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1146
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1147
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1148
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1149
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1150
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1151
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1152
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1153
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1154
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
1155
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
1156
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
1157
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
1158
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
1159
How do you diagnose gutteral pouch mycosis?
Endoscopy
1160
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
1161
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
1162
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
1163
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
1164
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
1165
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
1166
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
1167
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
1168
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1169
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1170
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1171
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1172
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1173
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1174
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1175
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1176
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1177
How big are pinworms?
2-13mm
1178
What is the proper name for pinworm?
Oxyuris equi
1179
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1180
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1181
What does atopy mean?
Hyperallergic
1182
How do you diagnose atopy?
Intradermal skin testing
1183
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1184
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1185
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1186
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1187
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1188
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1189
Give an antifungal used to treat ringworm?
Miconazole
1190
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1191
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1192
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1193
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1194
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1195
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1196
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1197
How do you treat a melanoma?
Surgical excision, immunotherapy
1198
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1199
Where are mast cell rumours found?
Head Solitary Males
1200
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1201
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1202
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1203
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1204
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1205
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1206
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1207
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1208
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1209
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1210
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1211
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1212
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1213
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1214
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1215
What percentage of colic cases require surgery?
7%
1216
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1217
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1218
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1219
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1220
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1221
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1222
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1223
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1224
What is the normal packed cell volume of a horse?
35-45%
1225
What is the normal value for systemic total protein?
60-70g/L
1226
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1227
What is the most common cause of colic in the foal?
Meconium impaction
1228
What is the medical term for equine grass sickness?
Equine dysautonomia
1229
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1230
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1231
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1232
What is the tidal volume of a horse at rest?
5L
1233
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1234
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1235
How do you work out minute ventilation?
Tidal volume x resp rate
1236
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1237
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1238
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1239
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1240
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1241
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1242
Is 'roaring' heard during inspiration or expiration?
Inspiration
1243
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1244
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1245
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1246
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1247
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1248
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1249
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1250
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1251
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1252
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1253
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1254
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1255
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1256
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1257
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1258
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1259
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1260
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1261
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1262
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1263
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1264
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1265
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1266
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1267
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1268
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1269
How does drainage of sinuses occur?
Gravity and mucociliary action
1270
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1271
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1272
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1273
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1274
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1275
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1276
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1277
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1278
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1279
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1280
How do you treat a paranasal sinus cyst?
Surgical removal
1281
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1282
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1283
What separates the nasopharynx from the oropharynx?
Soft palate
1284
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1285
How does the pharynx retain stability?
Coordinated neuromuscular function
1286
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1287
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1288
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1289
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1290
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1291
When does the glottis open and close?
Open: exercise Close: swallowing
1292
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1293
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1294
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1295
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1296
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1297
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1298
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1299
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1300
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1301
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1302
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1303
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1304
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1305
How would you identify a foal with cleft palate?
Milk at nostril
1306
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1307
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1308
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1309
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1310
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1311
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1312
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1313
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1314
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1315
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1316
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1317
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1318
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1319
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1320
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1321
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1322
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1323
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
1324
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
1325
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
1326
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
1327
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
1328
How do you diagnose gutteral pouch mycosis?
Endoscopy
1329
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
1330
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
1331
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
1332
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
1333
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
1334
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
1335
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
1336
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
1337
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1338
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1339
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1340
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1341
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1342
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1343
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1344
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1345
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1346
How big are pinworms?
2-13mm
1347
What is the proper name for pinworm?
Oxyuris equi
1348
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1349
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1350
What does atopy mean?
Hyperallergic
1351
How do you diagnose atopy?
Intradermal skin testing
1352
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1353
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1354
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1355
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1356
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1357
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1358
Give an antifungal used to treat ringworm?
Miconazole
1359
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1360
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1361
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1362
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1363
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1364
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1365
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1366
How do you treat a melanoma?
Surgical excision, immunotherapy
1367
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1368
Where are mast cell rumours found?
Head Solitary Males
1369
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1370
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1371
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1372
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1373
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1374
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1375
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1376
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1377
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1378
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1379
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1380
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1381
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1382
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1383
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1384
What percentage of colic cases require surgery?
7%
1385
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1386
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1387
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1388
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1389
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1390
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1391
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1392
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1393
What is the normal packed cell volume of a horse?
35-45%
1394
What is the normal value for systemic total protein?
60-70g/L
1395
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1396
What is the most common cause of colic in the foal?
Meconium impaction
1397
What is the medical term for equine grass sickness?
Equine dysautonomia
1398
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1399
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1400
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1401
What is the tidal volume of a horse at rest?
5L
1402
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1403
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1404
How do you work out minute ventilation?
Tidal volume x resp rate
1405
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1406
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1407
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1408
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1409
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1410
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1411
Is 'roaring' heard during inspiration or expiration?
Inspiration
1412
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1413
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1414
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1415
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1416
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1417
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1418
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1419
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1420
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1421
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1422
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1423
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1424
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1425
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1426
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1427
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1428
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1429
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1430
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1431
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1432
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1433
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1434
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1435
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1436
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1437
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1438
How does drainage of sinuses occur?
Gravity and mucociliary action
1439
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1440
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1441
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1442
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1443
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1444
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1445
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1446
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1447
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1448
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1449
How do you treat a paranasal sinus cyst?
Surgical removal
1450
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1451
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1452
What separates the nasopharynx from the oropharynx?
Soft palate
1453
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1454
How does the pharynx retain stability?
Coordinated neuromuscular function
1455
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1456
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1457
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1458
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1459
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1460
When does the glottis open and close?
Open: exercise Close: swallowing
1461
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1462
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1463
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1464
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1465
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1466
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1467
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1468
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1469
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1470
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1471
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1472
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1473
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1474
How would you identify a foal with cleft palate?
Milk at nostril
1475
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1476
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1477
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1478
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1479
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1480
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1481
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1482
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1483
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1484
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1485
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1486
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1487
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1488
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1489
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1490
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1491
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1492
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
1493
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
1494
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
1495
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
1496
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
1497
How do you diagnose gutteral pouch mycosis?
Endoscopy
1498
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
1499
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
1500
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
1501
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
1502
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
1503
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
1504
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
1505
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
1506
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1507
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1508
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1509
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1510
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1511
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1512
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1513
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1514
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1515
How big are pinworms?
2-13mm
1516
What is the proper name for pinworm?
Oxyuris equi
1517
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1518
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1519
What does atopy mean?
Hyperallergic
1520
How do you diagnose atopy?
Intradermal skin testing
1521
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1522
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1523
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1524
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1525
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1526
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1527
Give an antifungal used to treat ringworm?
Miconazole
1528
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1529
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1530
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1531
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1532
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1533
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1534
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1535
How do you treat a melanoma?
Surgical excision, immunotherapy
1536
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1537
Where are mast cell rumours found?
Head Solitary Males
1538
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1539
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1540
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1541
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1542
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1543
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1544
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1545
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1546
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1547
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1548
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1549
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1550
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1551
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1552
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1553
What percentage of colic cases require surgery?
7%
1554
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1555
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1556
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1557
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1558
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1559
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1560
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1561
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1562
What is the normal packed cell volume of a horse?
35-45%
1563
What is the normal value for systemic total protein?
60-70g/L
1564
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1565
What is the most common cause of colic in the foal?
Meconium impaction
1566
What is the medical term for equine grass sickness?
Equine dysautonomia
1567
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1568
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1569
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1570
What is the tidal volume of a horse at rest?
5L
1571
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1572
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1573
How do you work out minute ventilation?
Tidal volume x resp rate
1574
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1575
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1576
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1577
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1578
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1579
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1580
Is 'roaring' heard during inspiration or expiration?
Inspiration
1581
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1582
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1583
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1584
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1585
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1586
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1587
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1588
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1589
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1590
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1591
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1592
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1593
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1594
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1595
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1596
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1597
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1598
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1599
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1600
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1601
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1602
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1603
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1604
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1605
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1606
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1607
How does drainage of sinuses occur?
Gravity and mucociliary action
1608
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1609
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1610
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1611
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1612
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1613
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1614
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1615
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1616
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1617
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1618
How do you treat a paranasal sinus cyst?
Surgical removal
1619
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1620
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1621
What separates the nasopharynx from the oropharynx?
Soft palate
1622
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1623
How does the pharynx retain stability?
Coordinated neuromuscular function
1624
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1625
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1626
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1627
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1628
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1629
When does the glottis open and close?
Open: exercise Close: swallowing
1630
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1631
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1632
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1633
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1634
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1635
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1636
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1637
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1638
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1639
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1640
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1641
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1642
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1643
How would you identify a foal with cleft palate?
Milk at nostril
1644
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1645
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1646
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1647
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1648
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1649
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1650
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1651
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1652
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1653
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1654
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1655
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1656
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1657
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1658
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1659
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1660
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1661
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
1662
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
1663
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
1664
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
1665
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
1666
How do you diagnose gutteral pouch mycosis?
Endoscopy
1667
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
1668
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
1669
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
1670
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
1671
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
1672
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
1673
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
1674
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
1675
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1676
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1677
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1678
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1679
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1680
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1681
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1682
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1683
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1684
How big are pinworms?
2-13mm
1685
What is the proper name for pinworm?
Oxyuris equi
1686
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1687
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1688
What does atopy mean?
Hyperallergic
1689
How do you diagnose atopy?
Intradermal skin testing
1690
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1691
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1692
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1693
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1694
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1695
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1696
Give an antifungal used to treat ringworm?
Miconazole
1697
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1698
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1699
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1700
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1701
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1702
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1703
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1704
How do you treat a melanoma?
Surgical excision, immunotherapy
1705
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1706
Where are mast cell rumours found?
Head Solitary Males
1707
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1708
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1709
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1710
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1711
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1712
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1713
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1714
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1715
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1716
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1717
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1718
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1719
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1720
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1721
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1722
What percentage of colic cases require surgery?
7%
1723
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1724
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1725
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1726
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1727
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1728
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1729
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1730
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1731
What is the normal packed cell volume of a horse?
35-45%
1732
What is the normal value for systemic total protein?
60-70g/L
1733
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1734
What is the most common cause of colic in the foal?
Meconium impaction
1735
What is the medical term for equine grass sickness?
Equine dysautonomia
1736
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1737
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1738
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1739
What is the tidal volume of a horse at rest?
5L
1740
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1741
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1742
How do you work out minute ventilation?
Tidal volume x resp rate
1743
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1744
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1745
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1746
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1747
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1748
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1749
Is 'roaring' heard during inspiration or expiration?
Inspiration
1750
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1751
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1752
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1753
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1754
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1755
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1756
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1757
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1758
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1759
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1760
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1761
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1762
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1763
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1764
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1765
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1766
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1767
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1768
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1769
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1770
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1771
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1772
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1773
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1774
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1775
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1776
How does drainage of sinuses occur?
Gravity and mucociliary action
1777
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1778
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1779
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1780
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1781
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1782
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1783
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1784
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1785
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1786
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1787
How do you treat a paranasal sinus cyst?
Surgical removal
1788
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1789
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1790
What separates the nasopharynx from the oropharynx?
Soft palate
1791
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1792
How does the pharynx retain stability?
Coordinated neuromuscular function
1793
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1794
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1795
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1796
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1797
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1798
When does the glottis open and close?
Open: exercise Close: swallowing
1799
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1800
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1801
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1802
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1803
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1804
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1805
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1806
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1807
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1808
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1809
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1810
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1811
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1812
How would you identify a foal with cleft palate?
Milk at nostril
1813
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1814
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1815
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1816
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1817
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1818
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1819
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1820
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1821
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1822
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1823
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1824
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1825
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1826
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1827
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1828
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1829
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1830
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
1831
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
1832
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
1833
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
1834
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
1835
How do you diagnose gutteral pouch mycosis?
Endoscopy
1836
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
1837
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
1838
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
1839
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
1840
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
1841
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
1842
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
1843
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
1844
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
1845
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
1846
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
1847
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
1848
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
1849
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
1850
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
1851
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
1852
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
1853
How big are pinworms?
2-13mm
1854
What is the proper name for pinworm?
Oxyuris equi
1855
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
1856
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
1857
What does atopy mean?
Hyperallergic
1858
How do you diagnose atopy?
Intradermal skin testing
1859
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
1860
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
1861
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
1862
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
1863
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
1864
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
1865
Give an antifungal used to treat ringworm?
Miconazole
1866
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
1867
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
1868
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
1869
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
1870
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
1871
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
1872
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
1873
How do you treat a melanoma?
Surgical excision, immunotherapy
1874
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
1875
Where are mast cell rumours found?
Head Solitary Males
1876
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
1877
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
1878
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
1879
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
1880
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
1881
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
1882
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
1883
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
1884
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
1885
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
1886
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
1887
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
1888
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
1889
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
1890
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
1891
What percentage of colic cases require surgery?
7%
1892
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
1893
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
1894
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
1895
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
1896
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
1897
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
1898
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
1899
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
1900
What is the normal packed cell volume of a horse?
35-45%
1901
What is the normal value for systemic total protein?
60-70g/L
1902
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
1903
What is the most common cause of colic in the foal?
Meconium impaction
1904
What is the medical term for equine grass sickness?
Equine dysautonomia
1905
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
1906
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
1907
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
1908
What is the tidal volume of a horse at rest?
5L
1909
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
1910
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
1911
How do you work out minute ventilation?
Tidal volume x resp rate
1912
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
1913
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
1914
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
1915
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
1916
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
1917
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
1918
Is 'roaring' heard during inspiration or expiration?
Inspiration
1919
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
1920
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
1921
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
1922
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
1923
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
1924
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
1925
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
1926
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
1927
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
1928
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
1929
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
1930
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
1931
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
1932
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
1933
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
1934
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
1935
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
1936
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
1937
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
1938
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
1939
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
1940
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
1941
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
1942
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
1943
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
1944
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
1945
How does drainage of sinuses occur?
Gravity and mucociliary action
1946
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
1947
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
1948
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
1949
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
1950
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
1951
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
1952
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
1953
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
1954
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
1955
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
1956
How do you treat a paranasal sinus cyst?
Surgical removal
1957
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
1958
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
1959
What separates the nasopharynx from the oropharynx?
Soft palate
1960
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
1961
How does the pharynx retain stability?
Coordinated neuromuscular function
1962
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
1963
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
1964
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
1965
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
1966
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
1967
When does the glottis open and close?
Open: exercise Close: swallowing
1968
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
1969
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
1970
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
1971
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
1972
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
1973
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
1974
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
1975
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
1976
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
1977
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
1978
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
1979
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
1980
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
1981
How would you identify a foal with cleft palate?
Milk at nostril
1982
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
1983
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
1984
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
1985
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
1986
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
1987
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
1988
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
1989
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
1990
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
1991
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
1992
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
1993
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
1994
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
1995
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
1996
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
1997
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
1998
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
1999
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2000
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2001
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2002
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2003
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2004
How do you diagnose gutteral pouch mycosis?
Endoscopy
2005
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2006
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2007
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2008
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2009
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2010
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2011
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2012
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2013
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2014
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2015
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2016
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2017
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2018
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2019
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2020
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2021
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2022
How big are pinworms?
2-13mm
2023
What is the proper name for pinworm?
Oxyuris equi
2024
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2025
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2026
What does atopy mean?
Hyperallergic
2027
How do you diagnose atopy?
Intradermal skin testing
2028
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2029
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2030
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2031
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2032
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2033
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2034
Give an antifungal used to treat ringworm?
Miconazole
2035
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2036
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2037
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2038
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2039
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2040
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2041
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2042
How do you treat a melanoma?
Surgical excision, immunotherapy
2043
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2044
Where are mast cell rumours found?
Head Solitary Males
2045
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2046
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2047
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2048
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2049
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2050
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2051
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2052
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2053
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2054
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2055
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2056
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2057
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2058
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2059
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2060
What percentage of colic cases require surgery?
7%
2061
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2062
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2063
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2064
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2065
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2066
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2067
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2068
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2069
What is the normal packed cell volume of a horse?
35-45%
2070
What is the normal value for systemic total protein?
60-70g/L
2071
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2072
What is the most common cause of colic in the foal?
Meconium impaction
2073
What is the medical term for equine grass sickness?
Equine dysautonomia
2074
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2075
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2076
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2077
What is the tidal volume of a horse at rest?
5L
2078
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2079
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2080
How do you work out minute ventilation?
Tidal volume x resp rate
2081
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2082
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2083
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2084
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2085
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2086
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2087
Is 'roaring' heard during inspiration or expiration?
Inspiration
2088
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2089
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2090
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2091
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2092
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2093
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2094
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2095
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2096
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2097
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2098
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2099
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2100
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2101
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2102
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2103
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2104
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2105
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2106
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2107
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2108
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2109
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2110
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2111
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2112
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2113
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2114
How does drainage of sinuses occur?
Gravity and mucociliary action
2115
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2116
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2117
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2118
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2119
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2120
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2121
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2122
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2123
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2124
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2125
How do you treat a paranasal sinus cyst?
Surgical removal
2126
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2127
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2128
What separates the nasopharynx from the oropharynx?
Soft palate
2129
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2130
How does the pharynx retain stability?
Coordinated neuromuscular function
2131
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2132
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2133
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2134
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2135
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2136
When does the glottis open and close?
Open: exercise Close: swallowing
2137
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2138
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2139
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2140
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2141
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2142
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2143
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2144
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2145
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2146
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2147
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2148
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2149
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2150
How would you identify a foal with cleft palate?
Milk at nostril
2151
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2152
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2153
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2154
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
2155
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
2156
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
2157
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
2158
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
2159
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
2160
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
2161
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
2162
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
2163
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
2164
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
2165
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
2166
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
2167
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
2168
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2169
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2170
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2171
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2172
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2173
How do you diagnose gutteral pouch mycosis?
Endoscopy
2174
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2175
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2176
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2177
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2178
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2179
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2180
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2181
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2182
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2183
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2184
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2185
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2186
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2187
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2188
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2189
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2190
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2191
How big are pinworms?
2-13mm
2192
What is the proper name for pinworm?
Oxyuris equi
2193
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2194
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2195
What does atopy mean?
Hyperallergic
2196
How do you diagnose atopy?
Intradermal skin testing
2197
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2198
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2199
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2200
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2201
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2202
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2203
Give an antifungal used to treat ringworm?
Miconazole
2204
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2205
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2206
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2207
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2208
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2209
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2210
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2211
How do you treat a melanoma?
Surgical excision, immunotherapy
2212
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2213
Where are mast cell rumours found?
Head Solitary Males
2214
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2215
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2216
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2217
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2218
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2219
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2220
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2221
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2222
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2223
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2224
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2225
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2226
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2227
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2228
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2229
What percentage of colic cases require surgery?
7%
2230
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2231
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2232
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2233
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2234
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2235
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2236
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2237
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2238
What is the normal packed cell volume of a horse?
35-45%
2239
What is the normal value for systemic total protein?
60-70g/L
2240
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2241
What is the most common cause of colic in the foal?
Meconium impaction
2242
What is the medical term for equine grass sickness?
Equine dysautonomia
2243
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2244
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2245
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2246
What is the tidal volume of a horse at rest?
5L
2247
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2248
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2249
How do you work out minute ventilation?
Tidal volume x resp rate
2250
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2251
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2252
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2253
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2254
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2255
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2256
Is 'roaring' heard during inspiration or expiration?
Inspiration
2257
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2258
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2259
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2260
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2261
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2262
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2263
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2264
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2265
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2266
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2267
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2268
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2269
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2270
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2271
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2272
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2273
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2274
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2275
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2276
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2277
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2278
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2279
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2280
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2281
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2282
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2283
How does drainage of sinuses occur?
Gravity and mucociliary action
2284
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2285
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2286
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2287
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2288
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2289
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2290
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2291
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2292
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2293
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2294
How do you treat a paranasal sinus cyst?
Surgical removal
2295
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2296
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2297
What separates the nasopharynx from the oropharynx?
Soft palate
2298
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2299
How does the pharynx retain stability?
Coordinated neuromuscular function
2300
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2301
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2302
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2303
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2304
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2305
When does the glottis open and close?
Open: exercise Close: swallowing
2306
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2307
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2308
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2309
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2310
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2311
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2312
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2313
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2314
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2315
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2316
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2317
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2318
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2319
How would you identify a foal with cleft palate?
Milk at nostril
2320
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2321
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2322
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2323
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
2324
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
2325
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
2326
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
2327
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
2328
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
2329
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
2330
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
2331
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
2332
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
2333
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
2334
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
2335
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
2336
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
2337
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2338
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2339
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2340
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2341
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2342
How do you diagnose gutteral pouch mycosis?
Endoscopy
2343
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2344
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2345
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2346
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2347
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2348
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2349
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2350
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2351
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2352
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2353
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2354
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2355
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2356
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2357
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2358
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2359
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2360
How big are pinworms?
2-13mm
2361
What is the proper name for pinworm?
Oxyuris equi
2362
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2363
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2364
What does atopy mean?
Hyperallergic
2365
How do you diagnose atopy?
Intradermal skin testing
2366
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2367
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2368
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2369
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2370
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2371
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2372
Give an antifungal used to treat ringworm?
Miconazole
2373
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2374
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2375
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2376
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2377
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2378
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2379
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2380
How do you treat a melanoma?
Surgical excision, immunotherapy
2381
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2382
Where are mast cell rumours found?
Head Solitary Males
2383
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2384
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2385
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2386
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2387
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2388
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2389
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2390
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2391
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2392
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2393
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2394
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2395
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2396
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2397
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2398
What percentage of colic cases require surgery?
7%
2399
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2400
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2401
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2402
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2403
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2404
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2405
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2406
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2407
What is the normal packed cell volume of a horse?
35-45%
2408
What is the normal value for systemic total protein?
60-70g/L
2409
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2410
What is the most common cause of colic in the foal?
Meconium impaction
2411
What is the medical term for equine grass sickness?
Equine dysautonomia
2412
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2413
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2414
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2415
What is the tidal volume of a horse at rest?
5L
2416
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2417
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2418
How do you work out minute ventilation?
Tidal volume x resp rate
2419
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2420
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2421
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2422
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2423
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2424
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2425
Is 'roaring' heard during inspiration or expiration?
Inspiration
2426
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2427
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2428
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2429
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2430
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2431
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2432
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2433
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2434
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2435
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2436
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2437
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2438
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2439
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2440
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2441
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2442
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2443
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2444
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2445
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2446
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2447
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2448
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2449
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2450
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2451
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2452
How does drainage of sinuses occur?
Gravity and mucociliary action
2453
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2454
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2455
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2456
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2457
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2458
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2459
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2460
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2461
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2462
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2463
How do you treat a paranasal sinus cyst?
Surgical removal
2464
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2465
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2466
What separates the nasopharynx from the oropharynx?
Soft palate
2467
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2468
How does the pharynx retain stability?
Coordinated neuromuscular function
2469
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2470
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2471
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2472
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2473
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2474
When does the glottis open and close?
Open: exercise Close: swallowing
2475
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2476
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2477
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2478
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2479
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2480
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2481
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2482
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2483
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2484
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2485
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2486
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2487
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2488
How would you identify a foal with cleft palate?
Milk at nostril
2489
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2490
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2491
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2492
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
2493
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
2494
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
2495
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
2496
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
2497
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
2498
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
2499
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
2500
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
2501
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
2502
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
2503
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
2504
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
2505
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
2506
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2507
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2508
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2509
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2510
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2511
How do you diagnose gutteral pouch mycosis?
Endoscopy
2512
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2513
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2514
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2515
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2516
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2517
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2518
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2519
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2520
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2521
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2522
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2523
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2524
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2525
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2526
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2527
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2528
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2529
How big are pinworms?
2-13mm
2530
What is the proper name for pinworm?
Oxyuris equi
2531
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2532
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2533
What does atopy mean?
Hyperallergic
2534
How do you diagnose atopy?
Intradermal skin testing
2535
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2536
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2537
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2538
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2539
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2540
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2541
Give an antifungal used to treat ringworm?
Miconazole
2542
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2543
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2544
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2545
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2546
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2547
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2548
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2549
How do you treat a melanoma?
Surgical excision, immunotherapy
2550
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2551
Where are mast cell rumours found?
Head Solitary Males
2552
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2553
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2554
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2555
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2556
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2557
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2558
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2559
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2560
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2561
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2562
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2563
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2564
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2565
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2566
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2567
What percentage of colic cases require surgery?
7%
2568
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2569
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2570
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2571
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2572
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2573
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2574
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2575
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2576
What is the normal packed cell volume of a horse?
35-45%
2577
What is the normal value for systemic total protein?
60-70g/L
2578
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2579
What is the most common cause of colic in the foal?
Meconium impaction
2580
What is the medical term for equine grass sickness?
Equine dysautonomia
2581
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2582
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2583
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2584
What is the tidal volume of a horse at rest?
5L
2585
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2586
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2587
How do you work out minute ventilation?
Tidal volume x resp rate
2588
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2589
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2590
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2591
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2592
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2593
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2594
Is 'roaring' heard during inspiration or expiration?
Inspiration
2595
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2596
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2597
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2598
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2599
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2600
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2601
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2602
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2603
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2604
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2605
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2606
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2607
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2608
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2609
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2610
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2611
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2612
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2613
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2614
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2615
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2616
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2617
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2618
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2619
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2620
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2621
How does drainage of sinuses occur?
Gravity and mucociliary action
2622
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2623
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2624
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2625
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2626
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2627
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2628
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2629
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2630
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2631
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2632
How do you treat a paranasal sinus cyst?
Surgical removal
2633
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2634
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2635
What separates the nasopharynx from the oropharynx?
Soft palate
2636
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2637
How does the pharynx retain stability?
Coordinated neuromuscular function
2638
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2639
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2640
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2641
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2642
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2643
When does the glottis open and close?
Open: exercise Close: swallowing
2644
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2645
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2646
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2647
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2648
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2649
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2650
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2651
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2652
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2653
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2654
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2655
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2656
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2657
How would you identify a foal with cleft palate?
Milk at nostril
2658
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2659
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2660
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2661
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
2662
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
2663
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
2664
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
2665
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
2666
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
2667
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
2668
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
2669
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
2670
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
2671
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
2672
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
2673
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
2674
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
2675
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2676
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2677
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2678
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2679
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2680
How do you diagnose gutteral pouch mycosis?
Endoscopy
2681
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2682
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2683
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2684
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2685
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2686
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2687
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2688
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2689
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2690
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2691
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2692
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2693
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2694
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2695
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2696
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2697
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2698
How big are pinworms?
2-13mm
2699
What is the proper name for pinworm?
Oxyuris equi
2700
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2701
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2702
What does atopy mean?
Hyperallergic
2703
How do you diagnose atopy?
Intradermal skin testing
2704
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2705
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2706
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2707
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2708
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2709
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2710
Give an antifungal used to treat ringworm?
Miconazole
2711
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2712
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2713
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2714
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2715
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2716
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2717
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2718
How do you treat a melanoma?
Surgical excision, immunotherapy
2719
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2720
Where are mast cell rumours found?
Head Solitary Males
2721
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2722
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2723
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2724
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2725
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2726
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2727
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2728
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2729
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2730
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2731
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2732
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2733
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2734
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2735
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2736
What percentage of colic cases require surgery?
7%
2737
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2738
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2739
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2740
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2741
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2742
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2743
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2744
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2745
What is the normal packed cell volume of a horse?
35-45%
2746
What is the normal value for systemic total protein?
60-70g/L
2747
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2748
What is the most common cause of colic in the foal?
Meconium impaction
2749
What is the medical term for equine grass sickness?
Equine dysautonomia
2750
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2751
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2752
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2753
What is the tidal volume of a horse at rest?
5L
2754
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2755
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2756
How do you work out minute ventilation?
Tidal volume x resp rate
2757
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2758
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2759
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2760
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2761
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2762
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2763
Is 'roaring' heard during inspiration or expiration?
Inspiration
2764
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2765
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2766
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2767
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2768
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2769
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2770
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2771
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2772
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2773
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2774
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2775
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2776
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2777
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2778
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2779
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2780
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2781
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2782
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2783
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2784
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2785
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2786
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2787
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2788
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2789
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2790
How does drainage of sinuses occur?
Gravity and mucociliary action
2791
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2792
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2793
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2794
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2795
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2796
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2797
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2798
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2799
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2800
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2801
How do you treat a paranasal sinus cyst?
Surgical removal
2802
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2803
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2804
What separates the nasopharynx from the oropharynx?
Soft palate
2805
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2806
How does the pharynx retain stability?
Coordinated neuromuscular function
2807
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2808
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2809
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2810
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2811
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2812
When does the glottis open and close?
Open: exercise Close: swallowing
2813
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2814
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2815
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2816
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2817
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2818
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2819
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2820
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2821
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2822
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2823
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2824
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2825
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2826
How would you identify a foal with cleft palate?
Milk at nostril
2827
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2828
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2829
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2830
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
2831
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
2832
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
2833
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
2834
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
2835
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
2836
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
2837
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
2838
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
2839
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
2840
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
2841
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
2842
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
2843
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
2844
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
2845
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
2846
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
2847
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
2848
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
2849
How do you diagnose gutteral pouch mycosis?
Endoscopy
2850
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
2851
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
2852
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
2853
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
2854
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
2855
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
2856
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
2857
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
2858
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
2859
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
2860
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
2861
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
2862
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
2863
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
2864
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
2865
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
2866
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
2867
How big are pinworms?
2-13mm
2868
What is the proper name for pinworm?
Oxyuris equi
2869
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
2870
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
2871
What does atopy mean?
Hyperallergic
2872
How do you diagnose atopy?
Intradermal skin testing
2873
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
2874
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
2875
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
2876
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
2877
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
2878
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
2879
Give an antifungal used to treat ringworm?
Miconazole
2880
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
2881
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
2882
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
2883
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
2884
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
2885
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
2886
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
2887
How do you treat a melanoma?
Surgical excision, immunotherapy
2888
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
2889
Where are mast cell rumours found?
Head Solitary Males
2890
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
2891
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
2892
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
2893
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
2894
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
2895
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
2896
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
2897
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
2898
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
2899
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
2900
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
2901
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
2902
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
2903
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
2904
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
2905
What percentage of colic cases require surgery?
7%
2906
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
2907
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
2908
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
2909
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
2910
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
2911
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
2912
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
2913
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
2914
What is the normal packed cell volume of a horse?
35-45%
2915
What is the normal value for systemic total protein?
60-70g/L
2916
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
2917
What is the most common cause of colic in the foal?
Meconium impaction
2918
What is the medical term for equine grass sickness?
Equine dysautonomia
2919
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
2920
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
2921
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
2922
What is the tidal volume of a horse at rest?
5L
2923
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
2924
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
2925
How do you work out minute ventilation?
Tidal volume x resp rate
2926
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
2927
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
2928
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
2929
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
2930
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
2931
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
2932
Is 'roaring' heard during inspiration or expiration?
Inspiration
2933
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
2934
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
2935
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
2936
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
2937
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
2938
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
2939
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
2940
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
2941
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
2942
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
2943
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
2944
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
2945
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
2946
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
2947
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
2948
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
2949
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
2950
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
2951
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
2952
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
2953
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
2954
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
2955
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
2956
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
2957
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
2958
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
2959
How does drainage of sinuses occur?
Gravity and mucociliary action
2960
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
2961
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
2962
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
2963
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
2964
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
2965
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
2966
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
2967
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
2968
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
2969
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
2970
How do you treat a paranasal sinus cyst?
Surgical removal
2971
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
2972
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
2973
What separates the nasopharynx from the oropharynx?
Soft palate
2974
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
2975
How does the pharynx retain stability?
Coordinated neuromuscular function
2976
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
2977
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
2978
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
2979
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
2980
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
2981
When does the glottis open and close?
Open: exercise Close: swallowing
2982
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
2983
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
2984
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
2985
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
2986
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
2987
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
2988
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
2989
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
2990
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
2991
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
2992
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
2993
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
2994
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
2995
How would you identify a foal with cleft palate?
Milk at nostril
2996
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
2997
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
2998
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
2999
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3000
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3001
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3002
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3003
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3004
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3005
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3006
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3007
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3008
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3009
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3010
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3011
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3012
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3013
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3014
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3015
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3016
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3017
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3018
How do you diagnose gutteral pouch mycosis?
Endoscopy
3019
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3020
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3021
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3022
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3023
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3024
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3025
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3026
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3027
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3028
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3029
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3030
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3031
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3032
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3033
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3034
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3035
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3036
How big are pinworms?
2-13mm
3037
What is the proper name for pinworm?
Oxyuris equi
3038
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3039
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3040
What does atopy mean?
Hyperallergic
3041
How do you diagnose atopy?
Intradermal skin testing
3042
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3043
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3044
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3045
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3046
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3047
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3048
Give an antifungal used to treat ringworm?
Miconazole
3049
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3050
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3051
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3052
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3053
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3054
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3055
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3056
How do you treat a melanoma?
Surgical excision, immunotherapy
3057
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3058
Where are mast cell rumours found?
Head Solitary Males
3059
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3060
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3061
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3062
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3063
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3064
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3065
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3066
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3067
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3068
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3069
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3070
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3071
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3072
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3073
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3074
What percentage of colic cases require surgery?
7%
3075
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3076
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3077
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3078
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3079
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3080
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3081
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3082
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3083
What is the normal packed cell volume of a horse?
35-45%
3084
What is the normal value for systemic total protein?
60-70g/L
3085
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3086
What is the most common cause of colic in the foal?
Meconium impaction
3087
What is the medical term for equine grass sickness?
Equine dysautonomia
3088
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3089
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3090
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3091
What is the tidal volume of a horse at rest?
5L
3092
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3093
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3094
How do you work out minute ventilation?
Tidal volume x resp rate
3095
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3096
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3097
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3098
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3099
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3100
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3101
Is 'roaring' heard during inspiration or expiration?
Inspiration
3102
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3103
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3104
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3105
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3106
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3107
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3108
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3109
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3110
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3111
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3112
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3113
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3114
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3115
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3116
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3117
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3118
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3119
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3120
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3121
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3122
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3123
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3124
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3125
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3126
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3127
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3128
How does drainage of sinuses occur?
Gravity and mucociliary action
3129
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3130
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3131
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3132
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3133
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3134
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3135
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3136
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3137
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3138
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3139
How do you treat a paranasal sinus cyst?
Surgical removal
3140
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3141
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3142
What separates the nasopharynx from the oropharynx?
Soft palate
3143
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3144
How does the pharynx retain stability?
Coordinated neuromuscular function
3145
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3146
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3147
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3148
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3149
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3150
When does the glottis open and close?
Open: exercise Close: swallowing
3151
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3152
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3153
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3154
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
3155
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
3156
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
3157
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
3158
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
3159
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
3160
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
3161
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
3162
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
3163
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
3164
How would you identify a foal with cleft palate?
Milk at nostril
3165
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
3166
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
3167
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
3168
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3169
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3170
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3171
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3172
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3173
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3174
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3175
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3176
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3177
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3178
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3179
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3180
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3181
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3182
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3183
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3184
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3185
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3186
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3187
How do you diagnose gutteral pouch mycosis?
Endoscopy
3188
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3189
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3190
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3191
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3192
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3193
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3194
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3195
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3196
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3197
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3198
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3199
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3200
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3201
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3202
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3203
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3204
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3205
How big are pinworms?
2-13mm
3206
What is the proper name for pinworm?
Oxyuris equi
3207
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3208
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3209
What does atopy mean?
Hyperallergic
3210
How do you diagnose atopy?
Intradermal skin testing
3211
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3212
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3213
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3214
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3215
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3216
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3217
Give an antifungal used to treat ringworm?
Miconazole
3218
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3219
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3220
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3221
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3222
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3223
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3224
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3225
How do you treat a melanoma?
Surgical excision, immunotherapy
3226
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3227
Where are mast cell rumours found?
Head Solitary Males
3228
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3229
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3230
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3231
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3232
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3233
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3234
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3235
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3236
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3237
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3238
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3239
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3240
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3241
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3242
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3243
What percentage of colic cases require surgery?
7%
3244
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3245
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3246
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3247
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3248
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3249
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3250
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3251
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3252
What is the normal packed cell volume of a horse?
35-45%
3253
What is the normal value for systemic total protein?
60-70g/L
3254
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3255
What is the most common cause of colic in the foal?
Meconium impaction
3256
What is the medical term for equine grass sickness?
Equine dysautonomia
3257
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3258
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3259
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3260
What is the tidal volume of a horse at rest?
5L
3261
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3262
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3263
How do you work out minute ventilation?
Tidal volume x resp rate
3264
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3265
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3266
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3267
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3268
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3269
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3270
Is 'roaring' heard during inspiration or expiration?
Inspiration
3271
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3272
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3273
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3274
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3275
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3276
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3277
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3278
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3279
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3280
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3281
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3282
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3283
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3284
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3285
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3286
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3287
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3288
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3289
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3290
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3291
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3292
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3293
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3294
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3295
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3296
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3297
How does drainage of sinuses occur?
Gravity and mucociliary action
3298
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3299
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3300
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3301
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3302
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3303
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3304
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3305
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3306
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3307
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3308
How do you treat a paranasal sinus cyst?
Surgical removal
3309
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3310
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3311
What separates the nasopharynx from the oropharynx?
Soft palate
3312
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3313
How does the pharynx retain stability?
Coordinated neuromuscular function
3314
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3315
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3316
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3317
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3318
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3319
When does the glottis open and close?
Open: exercise Close: swallowing
3320
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3321
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3322
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3323
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
3324
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
3325
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
3326
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
3327
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
3328
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
3329
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
3330
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
3331
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
3332
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
3333
How would you identify a foal with cleft palate?
Milk at nostril
3334
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
3335
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
3336
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
3337
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3338
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3339
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3340
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3341
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3342
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3343
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3344
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3345
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3346
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3347
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3348
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3349
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3350
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3351
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3352
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3353
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3354
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3355
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3356
How do you diagnose gutteral pouch mycosis?
Endoscopy
3357
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3358
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3359
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3360
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3361
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3362
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3363
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3364
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3365
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3366
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3367
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3368
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3369
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3370
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3371
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3372
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3373
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3374
How big are pinworms?
2-13mm
3375
What is the proper name for pinworm?
Oxyuris equi
3376
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3377
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3378
What does atopy mean?
Hyperallergic
3379
How do you diagnose atopy?
Intradermal skin testing
3380
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3381
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3382
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3383
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3384
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3385
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3386
Give an antifungal used to treat ringworm?
Miconazole
3387
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3388
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3389
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3390
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3391
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3392
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3393
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3394
How do you treat a melanoma?
Surgical excision, immunotherapy
3395
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3396
Where are mast cell rumours found?
Head Solitary Males
3397
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3398
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3399
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3400
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3401
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3402
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3403
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3404
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3405
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3406
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3407
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3408
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3409
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3410
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3411
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3412
What percentage of colic cases require surgery?
7%
3413
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3414
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3415
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3416
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3417
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3418
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3419
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3420
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3421
What is the normal packed cell volume of a horse?
35-45%
3422
What is the normal value for systemic total protein?
60-70g/L
3423
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3424
What is the most common cause of colic in the foal?
Meconium impaction
3425
What is the medical term for equine grass sickness?
Equine dysautonomia
3426
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3427
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3428
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3429
What is the tidal volume of a horse at rest?
5L
3430
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3431
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3432
How do you work out minute ventilation?
Tidal volume x resp rate
3433
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3434
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3435
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3436
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3437
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3438
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3439
Is 'roaring' heard during inspiration or expiration?
Inspiration
3440
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3441
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3442
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3443
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3444
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3445
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3446
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3447
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3448
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3449
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3450
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3451
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3452
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3453
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3454
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3455
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3456
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3457
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3458
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3459
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3460
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3461
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3462
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3463
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3464
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3465
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3466
How does drainage of sinuses occur?
Gravity and mucociliary action
3467
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3468
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3469
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3470
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3471
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3472
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3473
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3474
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3475
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3476
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3477
How do you treat a paranasal sinus cyst?
Surgical removal
3478
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3479
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3480
What separates the nasopharynx from the oropharynx?
Soft palate
3481
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3482
How does the pharynx retain stability?
Coordinated neuromuscular function
3483
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3484
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3485
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3486
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3487
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3488
When does the glottis open and close?
Open: exercise Close: swallowing
3489
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3490
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3491
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3492
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
3493
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
3494
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
3495
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
3496
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
3497
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
3498
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
3499
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
3500
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
3501
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
3502
How would you identify a foal with cleft palate?
Milk at nostril
3503
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
3504
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
3505
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
3506
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3507
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3508
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3509
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3510
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3511
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3512
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3513
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3514
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3515
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3516
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3517
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3518
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3519
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3520
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3521
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3522
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3523
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3524
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3525
How do you diagnose gutteral pouch mycosis?
Endoscopy
3526
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3527
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3528
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3529
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3530
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3531
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3532
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3533
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3534
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3535
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3536
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3537
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3538
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3539
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3540
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3541
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3542
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3543
How big are pinworms?
2-13mm
3544
What is the proper name for pinworm?
Oxyuris equi
3545
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3546
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3547
What does atopy mean?
Hyperallergic
3548
How do you diagnose atopy?
Intradermal skin testing
3549
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3550
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3551
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3552
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3553
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3554
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3555
Give an antifungal used to treat ringworm?
Miconazole
3556
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3557
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3558
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3559
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3560
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3561
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3562
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3563
How do you treat a melanoma?
Surgical excision, immunotherapy
3564
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3565
Where are mast cell rumours found?
Head Solitary Males
3566
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3567
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3568
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3569
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3570
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3571
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3572
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3573
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3574
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3575
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3576
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3577
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3578
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3579
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3580
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3581
What percentage of colic cases require surgery?
7%
3582
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3583
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3584
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3585
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3586
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3587
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3588
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3589
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3590
What is the normal packed cell volume of a horse?
35-45%
3591
What is the normal value for systemic total protein?
60-70g/L
3592
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3593
What is the most common cause of colic in the foal?
Meconium impaction
3594
What is the medical term for equine grass sickness?
Equine dysautonomia
3595
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3596
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3597
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3598
What is the tidal volume of a horse at rest?
5L
3599
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3600
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3601
How do you work out minute ventilation?
Tidal volume x resp rate
3602
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3603
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3604
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3605
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3606
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3607
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3608
Is 'roaring' heard during inspiration or expiration?
Inspiration
3609
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3610
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3611
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3612
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3613
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3614
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3615
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3616
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3617
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3618
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3619
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3620
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3621
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3622
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3623
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3624
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3625
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3626
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3627
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3628
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3629
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3630
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3631
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3632
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3633
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3634
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3635
How does drainage of sinuses occur?
Gravity and mucociliary action
3636
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3637
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3638
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3639
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3640
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3641
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3642
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3643
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3644
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3645
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3646
How do you treat a paranasal sinus cyst?
Surgical removal
3647
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3648
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3649
What separates the nasopharynx from the oropharynx?
Soft palate
3650
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3651
How does the pharynx retain stability?
Coordinated neuromuscular function
3652
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3653
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3654
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3655
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3656
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3657
When does the glottis open and close?
Open: exercise Close: swallowing
3658
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3659
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3660
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3661
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
3662
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
3663
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
3664
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
3665
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
3666
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
3667
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
3668
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
3669
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
3670
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
3671
How would you identify a foal with cleft palate?
Milk at nostril
3672
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
3673
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
3674
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
3675
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3676
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3677
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3678
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3679
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3680
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3681
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3682
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3683
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3684
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3685
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3686
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3687
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3688
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3689
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3690
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3691
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3692
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3693
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3694
How do you diagnose gutteral pouch mycosis?
Endoscopy
3695
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3696
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3697
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3698
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3699
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3700
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3701
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3702
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3703
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3704
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3705
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3706
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3707
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3708
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3709
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3710
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3711
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3712
How big are pinworms?
2-13mm
3713
What is the proper name for pinworm?
Oxyuris equi
3714
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3715
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3716
What does atopy mean?
Hyperallergic
3717
How do you diagnose atopy?
Intradermal skin testing
3718
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3719
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3720
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3721
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3722
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3723
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3724
Give an antifungal used to treat ringworm?
Miconazole
3725
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3726
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3727
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3728
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3729
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3730
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3731
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3732
How do you treat a melanoma?
Surgical excision, immunotherapy
3733
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3734
Where are mast cell rumours found?
Head Solitary Males
3735
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3736
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3737
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3738
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3739
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3740
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3741
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3742
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3743
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3744
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3745
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3746
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3747
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3748
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3749
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3750
What percentage of colic cases require surgery?
7%
3751
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3752
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3753
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3754
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3755
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3756
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3757
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3758
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3759
What is the normal packed cell volume of a horse?
35-45%
3760
What is the normal value for systemic total protein?
60-70g/L
3761
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3762
What is the most common cause of colic in the foal?
Meconium impaction
3763
What is the medical term for equine grass sickness?
Equine dysautonomia
3764
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3765
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3766
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3767
What is the tidal volume of a horse at rest?
5L
3768
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3769
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3770
How do you work out minute ventilation?
Tidal volume x resp rate
3771
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3772
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3773
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3774
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3775
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3776
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3777
Is 'roaring' heard during inspiration or expiration?
Inspiration
3778
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3779
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3780
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3781
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3782
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3783
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3784
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3785
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3786
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3787
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3788
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3789
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3790
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3791
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3792
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3793
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3794
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3795
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3796
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3797
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3798
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3799
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3800
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3801
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3802
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3803
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3804
How does drainage of sinuses occur?
Gravity and mucociliary action
3805
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3806
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3807
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3808
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3809
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3810
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3811
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3812
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3813
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3814
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3815
How do you treat a paranasal sinus cyst?
Surgical removal
3816
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3817
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3818
What separates the nasopharynx from the oropharynx?
Soft palate
3819
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3820
How does the pharynx retain stability?
Coordinated neuromuscular function
3821
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3822
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3823
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3824
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3825
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3826
When does the glottis open and close?
Open: exercise Close: swallowing
3827
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3828
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3829
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3830
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
3831
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
3832
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
3833
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
3834
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
3835
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
3836
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
3837
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
3838
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
3839
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
3840
How would you identify a foal with cleft palate?
Milk at nostril
3841
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
3842
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
3843
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
3844
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
3845
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
3846
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
3847
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
3848
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
3849
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
3850
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
3851
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
3852
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
3853
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
3854
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
3855
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
3856
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
3857
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
3858
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
3859
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
3860
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
3861
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
3862
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
3863
How do you diagnose gutteral pouch mycosis?
Endoscopy
3864
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
3865
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
3866
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
3867
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
3868
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
3869
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
3870
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
3871
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
3872
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
3873
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
3874
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
3875
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
3876
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
3877
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
3878
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
3879
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
3880
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
3881
How big are pinworms?
2-13mm
3882
What is the proper name for pinworm?
Oxyuris equi
3883
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
3884
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
3885
What does atopy mean?
Hyperallergic
3886
How do you diagnose atopy?
Intradermal skin testing
3887
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
3888
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
3889
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
3890
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
3891
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
3892
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
3893
Give an antifungal used to treat ringworm?
Miconazole
3894
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
3895
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
3896
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
3897
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
3898
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
3899
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
3900
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
3901
How do you treat a melanoma?
Surgical excision, immunotherapy
3902
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
3903
Where are mast cell rumours found?
Head Solitary Males
3904
How is equine herpes virus spread?
Mainly be respiratory route | Aborted foetus/ membranes/ vaginal discharge are highly contagious
3905
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
3906
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
3907
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
3908
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
3909
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
3910
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
3911
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
3912
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
3913
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
3914
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
3915
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
3916
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
3917
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
3918
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
3919
What percentage of colic cases require surgery?
7%
3920
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
3921
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
3922
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
3923
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
3924
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
3925
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
3926
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
3927
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
3928
What is the normal packed cell volume of a horse?
35-45%
3929
What is the normal value for systemic total protein?
60-70g/L
3930
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
3931
What is the most common cause of colic in the foal?
Meconium impaction
3932
What is the medical term for equine grass sickness?
Equine dysautonomia
3933
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
3934
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
3935
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
3936
What is the tidal volume of a horse at rest?
5L
3937
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
3938
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
3939
How do you work out minute ventilation?
Tidal volume x resp rate
3940
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
3941
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
3942
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
3943
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
3944
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
3945
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
3946
Is 'roaring' heard during inspiration or expiration?
Inspiration
3947
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
3948
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
3949
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
3950
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
3951
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
3952
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
3953
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
3954
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
3955
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
3956
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
3957
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
3958
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
3959
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
3960
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
3961
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
3962
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
3963
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
3964
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
3965
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
3966
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
3967
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
3968
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
3969
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
3970
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
3971
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
3972
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
3973
How does drainage of sinuses occur?
Gravity and mucociliary action
3974
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
3975
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
3976
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
3977
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
3978
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
3979
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
3980
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
3981
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
3982
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
3983
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
3984
How do you treat a paranasal sinus cyst?
Surgical removal
3985
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
3986
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
3987
What separates the nasopharynx from the oropharynx?
Soft palate
3988
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
3989
How does the pharynx retain stability?
Coordinated neuromuscular function
3990
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
3991
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
3992
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
3993
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
3994
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
3995
When does the glottis open and close?
Open: exercise Close: swallowing
3996
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
3997
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
3998
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
3999
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4000
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4001
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4002
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4003
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4004
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4005
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4006
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4007
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4008
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4009
How would you identify a foal with cleft palate?
Milk at nostril
4010
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4011
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4012
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4013
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4014
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4015
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4016
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4017
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4018
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4019
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4020
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4021
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4022
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4023
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4024
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4025
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4026
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4027
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4028
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4029
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4030
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4031
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4032
How do you diagnose gutteral pouch mycosis?
Endoscopy
4033
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4034
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4035
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4036
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4037
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4038
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4039
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4040
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4041
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4042
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4043
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4044
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4045
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4046
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4047
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4048
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4049
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4050
How big are pinworms?
2-13mm
4051
What is the proper name for pinworm?
Oxyuris equi
4052
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4053
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4054
What does atopy mean?
Hyperallergic
4055
How do you diagnose atopy?
Intradermal skin testing
4056
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4057
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4058
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4059
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4060
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4061
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4062
Give an antifungal used to treat ringworm?
Miconazole
4063
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4064
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4065
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4066
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4067
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4068
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4069
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4070
How do you treat a melanoma?
Surgical excision, immunotherapy
4071
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4072
Where are mast cell rumours found?
Head Solitary Males
4073
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
4074
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
4075
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
4076
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
4077
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
4078
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
4079
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
4080
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
4081
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
4082
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
4083
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
4084
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
4085
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
4086
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
4087
What percentage of colic cases require surgery?
7%
4088
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
4089
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
4090
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
4091
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
4092
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
4093
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
4094
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
4095
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
4096
What is the normal packed cell volume of a horse?
35-45%
4097
What is the normal value for systemic total protein?
60-70g/L
4098
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
4099
What is the most common cause of colic in the foal?
Meconium impaction
4100
What is the medical term for equine grass sickness?
Equine dysautonomia
4101
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
4102
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
4103
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
4104
What is the tidal volume of a horse at rest?
5L
4105
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
4106
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
4107
How do you work out minute ventilation?
Tidal volume x resp rate
4108
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
4109
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
4110
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
4111
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
4112
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
4113
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
4114
Is 'roaring' heard during inspiration or expiration?
Inspiration
4115
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
4116
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
4117
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
4118
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
4119
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
4120
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
4121
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
4122
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
4123
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
4124
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
4125
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
4126
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
4127
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
4128
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
4129
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
4130
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
4131
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
4132
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
4133
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
4134
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
4135
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
4136
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
4137
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
4138
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
4139
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
4140
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
4141
How does drainage of sinuses occur?
Gravity and mucociliary action
4142
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
4143
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
4144
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
4145
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
4146
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
4147
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
4148
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
4149
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
4150
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
4151
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
4152
How do you treat a paranasal sinus cyst?
Surgical removal
4153
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
4154
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
4155
What separates the nasopharynx from the oropharynx?
Soft palate
4156
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
4157
How does the pharynx retain stability?
Coordinated neuromuscular function
4158
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
4159
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
4160
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
4161
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
4162
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
4163
When does the glottis open and close?
Open: exercise Close: swallowing
4164
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
4165
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
4166
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
4167
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4168
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4169
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4170
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4171
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4172
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4173
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4174
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4175
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4176
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4177
How would you identify a foal with cleft palate?
Milk at nostril
4178
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4179
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4180
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4181
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4182
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4183
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4184
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4185
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4186
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4187
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4188
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4189
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4190
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4191
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4192
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4193
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4194
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4195
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4196
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4197
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4198
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4199
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4200
How do you diagnose gutteral pouch mycosis?
Endoscopy
4201
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4202
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4203
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4204
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4205
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4206
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4207
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4208
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4209
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4210
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4211
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4212
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4213
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4214
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4215
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4216
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4217
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4218
How big are pinworms?
2-13mm
4219
What is the proper name for pinworm?
Oxyuris equi
4220
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4221
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4222
What does atopy mean?
Hyperallergic
4223
How do you diagnose atopy?
Intradermal skin testing
4224
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4225
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4226
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4227
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4228
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4229
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4230
Give an antifungal used to treat ringworm?
Miconazole
4231
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4232
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4233
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4234
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4235
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4236
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4237
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4238
How do you treat a melanoma?
Surgical excision, immunotherapy
4239
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4240
Where are mast cell rumours found?
Head Solitary Males
4241
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
4242
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
4243
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
4244
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
4245
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
4246
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
4247
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
4248
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
4249
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
4250
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
4251
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
4252
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
4253
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
4254
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
4255
What percentage of colic cases require surgery?
7%
4256
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
4257
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
4258
Which questions should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
4259
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
4260
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
4261
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
4262
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
4263
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
4264
What is the normal packed cell volume of a horse?
35-45%
4265
What is the normal value for systemic total protein?
60-70g/L
4266
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
4267
What is the most common cause of colic in the foal?
Meconium impaction
4268
What is the medical term for equine grass sickness?
Equine dysautonomia
4269
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
4270
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
4271
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
4272
What is the tidal volume of a horse at rest?
5L
4273
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
4274
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
4275
How do you work out minute ventilation?
Tidal volume x resp rate
4276
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
4277
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
4278
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
4279
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
4280
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
4281
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
4282
Is 'roaring' heard during inspiration or expiration?
Inspiration
4283
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
4284
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
4285
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
4286
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
4287
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
4288
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
4289
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
4290
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
4291
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
4292
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
4293
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
4294
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
4295
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
4296
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
4297
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
4298
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
4299
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
4300
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
4301
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
4302
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
4303
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
4304
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
4305
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
4306
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
4307
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
4308
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
4309
How does drainage of sinuses occur?
Gravity and mucociliary action
4310
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
4311
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
4312
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
4313
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
4314
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
4315
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
4316
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
4317
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
4318
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
4319
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
4320
How do you treat a paranasal sinus cyst?
Surgical removal
4321
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
4322
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
4323
What separates the nasopharynx from the oropharynx?
Soft palate
4324
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
4325
How does the pharynx retain stability?
Coordinated neuromuscular function
4326
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
4327
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
4328
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
4329
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
4330
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
4331
When does the glottis open and close?
Open: exercise Close: swallowing
4332
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
4333
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
4334
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
4335
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4336
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4337
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4338
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4339
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4340
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4341
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4342
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4343
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4344
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4345
How would you identify a foal with cleft palate?
Milk at nostril
4346
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4347
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4348
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4349
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4350
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4351
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4352
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4353
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4354
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4355
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4356
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4357
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4358
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4359
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4360
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4361
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4362
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4363
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4364
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4365
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4366
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4367
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4368
How do you diagnose gutteral pouch mycosis?
Endoscopy
4369
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4370
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4371
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4372
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4373
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4374
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4375
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4376
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4377
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4378
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4379
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4380
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4381
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4382
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4383
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4384
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4385
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4386
How big are pinworms?
2-13mm
4387
What is the proper name for pinworm?
Oxyuris equi
4388
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4389
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4390
What does atopy mean?
Hyperallergic
4391
How do you diagnose atopy?
Intradermal skin testing
4392
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4393
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4394
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4395
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4396
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4397
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4398
Give an antifungal used to treat ringworm?
Miconazole
4399
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4400
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4401
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4402
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4403
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4404
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4405
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4406
How do you treat a melanoma?
Surgical excision, immunotherapy
4407
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4408
Where are mast cell rumours found?
Head Solitary Males
4409
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
4410
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
4411
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
4412
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
4413
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
4414
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
4415
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
4416
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
4417
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
4418
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
4419
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
4420
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
4421
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
4422
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
4423
What percentage of colic cases require surgery?
7%
4424
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
4425
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
4426
Which queens should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
4427
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
4428
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
4429
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
4430
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
4431
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
4432
What is the normal packed cell volume of a horse?
35-45%
4433
What is the normal value for systemic total protein?
60-70g/L
4434
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
4435
What is the most common cause of colic in the foal?
Meconium impaction
4436
What is the medical term for equine grass sickness?
Equine dysautonomia
4437
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
4438
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
4439
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
4440
What is the tidal volume of a horse at rest?
5L
4441
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
4442
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
4443
How do you work out minute ventilation?
Tidal volume x resp rate
4444
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
4445
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
4446
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
4447
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
4448
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
4449
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
4450
Is 'roaring' heard during inspiration or expiration?
Inspiration
4451
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
4452
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
4453
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
4454
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
4455
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
4456
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
4457
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
4458
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
4459
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
4460
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
4461
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
4462
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
4463
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
4464
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
4465
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
4466
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
4467
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
4468
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
4469
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
4470
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
4471
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
4472
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
4473
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
4474
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
4475
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
4476
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
4477
How does drainage of sinuses occur?
Gravity and mucociliary action
4478
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
4479
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
4480
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
4481
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
4482
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
4483
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
4484
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
4485
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
4486
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
4487
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
4488
How do you treat a paranasal sinus cyst?
Surgical removal
4489
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
4490
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
4491
What separates the nasopharynx from the oropharynx?
Soft palate
4492
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
4493
How does the pharynx retain stability?
Coordinated neuromuscular function
4494
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
4495
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
4496
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
4497
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
4498
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
4499
When does the glottis open and close?
Open: exercise Close: swallowing
4500
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
4501
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
4502
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
4503
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4504
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4505
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4506
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4507
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4508
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4509
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4510
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4511
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4512
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4513
How would you identify a foal with cleft palate?
Milk at nostril
4514
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4515
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4516
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4517
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4518
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4519
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4520
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4521
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4522
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4523
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4524
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4525
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4526
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4527
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4528
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4529
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4530
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4531
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4532
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4533
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4534
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4535
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4536
How do you diagnose gutteral pouch mycosis?
Endoscopy
4537
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4538
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4539
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4540
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4541
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4542
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4543
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4544
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4545
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4546
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4547
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4548
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4549
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4550
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4551
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4552
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4553
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4554
How big are pinworms?
2-13mm
4555
What is the proper name for pinworm?
Oxyuris equi
4556
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4557
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4558
What does atopy mean?
Hyperallergic
4559
How do you diagnose atopy?
Intradermal skin testing
4560
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4561
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4562
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4563
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4564
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4565
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4566
Give an antifungal used to treat ringworm?
Miconazole
4567
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4568
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4569
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4570
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4571
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4572
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4573
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4574
How do you treat a melanoma?
Surgical excision, immunotherapy
4575
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4576
Where are mast cell rumours found?
Head Solitary Males
4577
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
4578
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
4579
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
4580
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
4581
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
4582
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
4583
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
4584
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
4585
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
4586
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
4587
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
4588
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
4589
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
4590
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
4591
What percentage of colic cases require surgery?
7%
4592
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
4593
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
4594
Which queens should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
4595
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
4596
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
4597
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
4598
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
4599
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
4600
What is the normal packed cell volume of a horse?
35-45%
4601
What is the normal value for systemic total protein?
60-70g/L
4602
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
4603
What is the most common cause of colic in the foal?
Meconium impaction
4604
What is the medical term for equine grass sickness?
Equine dysautonomia
4605
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
4606
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
4607
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
4608
What is the tidal volume of a horse at rest?
5L
4609
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
4610
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
4611
How do you work out minute ventilation?
Tidal volume x resp rate
4612
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
4613
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
4614
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
4615
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
4616
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
4617
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
4618
Is 'roaring' heard during inspiration or expiration?
Inspiration
4619
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
4620
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
4621
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
4622
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
4623
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
4624
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
4625
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
4626
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
4627
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
4628
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
4629
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
4630
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
4631
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
4632
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
4633
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
4634
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
4635
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
4636
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
4637
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
4638
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
4639
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
4640
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
4641
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
4642
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
4643
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
4644
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
4645
How does drainage of sinuses occur?
Gravity and mucociliary action
4646
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
4647
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
4648
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
4649
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
4650
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
4651
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
4652
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
4653
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
4654
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
4655
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
4656
How do you treat a paranasal sinus cyst?
Surgical removal
4657
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
4658
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
4659
What separates the nasopharynx from the oropharynx?
Soft palate
4660
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
4661
How does the pharynx retain stability?
Coordinated neuromuscular function
4662
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
4663
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
4664
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
4665
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
4666
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
4667
When does the glottis open and close?
Open: exercise Close: swallowing
4668
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
4669
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
4670
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
4671
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4672
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4673
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4674
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4675
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4676
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4677
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4678
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4679
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4680
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4681
How would you identify a foal with cleft palate?
Milk at nostril
4682
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4683
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4684
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4685
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4686
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4687
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4688
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4689
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4690
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4691
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4692
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4693
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4694
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4695
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4696
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4697
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4698
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4699
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4700
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4701
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4702
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4703
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4704
How do you diagnose gutteral pouch mycosis?
Endoscopy
4705
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4706
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4707
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4708
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4709
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4710
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4711
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4712
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4713
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4714
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4715
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4716
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4717
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4718
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4719
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4720
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4721
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4722
How big are pinworms?
2-13mm
4723
What is the proper name for pinworm?
Oxyuris equi
4724
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4725
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4726
What does atopy mean?
Hyperallergic
4727
How do you diagnose atopy?
Intradermal skin testing
4728
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4729
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4730
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4731
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4732
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4733
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4734
Give an antifungal used to treat ringworm?
Miconazole
4735
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4736
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4737
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4738
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4739
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4740
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4741
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4742
How do you treat a melanoma?
Surgical excision, immunotherapy
4743
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4744
Where are mast cell rumours found?
Head Solitary Males
4745
How do large and small strongyles affect the colon?
Large: verminous arteritis, thromboembolic colic Small: submucosal inflammation
4746
Give some haematological changes associated with parasitism?
Neutrophilia, hypoalbuminaemia, hyperglobulinaemia NOT eosinophilia
4747
What are the two divisions of equine gastric ulcer syndrome? | Give possible risk factors for each
EGGUS: Equine glandular gastric ulcer syndrome (bother horses mοre, harder to treat). Risk factors= possibly stress, NSAID-related. ESGUS: Equine squamous gastric ulcer syndrome. Risk factor= acid injury.
4748
What are the signs of EGUS (equine gastric ulcer syndrome)?
Weight loss, poor performance Selective appetite, slow eating, prefer roughage over grain Bad/cranky behaviou Colic very unlikely
4749
What is the pH in the two parts of the stomach?
Squamous portion prone to acid injury: pH 5.4 | Glandular, acid-secreting portion protected from acid injury by mucous layer: 1.8
4750
Where do ESGUS and EGGUS usually occur?
ESGUS: Caused by 'splashing' of stomach acid onto the unprotected mucosal lining above the margo plicatus, on squamous portion of stomach EGGUS: below margo plicatus on glandular portion of stomach, when protective lining breaks down, exposing the mucosa to acids
4751
Why is the horse so susceptible to gastric ulcers?
Stomach anatomy -> poor mixing of food, grain portion is rapidly fermentable -> acid production
4752
Give some predisposing factors to acid injury leading to gastric ulcers
High concentrate diets -> volatile fatty acids and indirect acid injury via gastrin production in response to absorbed CHO (carbohydrates) Also, low fibre concentrations -> reduced saliva production (saliva is an acid buffer) Exercise -> gastrin production, also increased abdominal pressure can promote 'splashing' of acid onto unprotected squamous portion
4753
How do you diagnose gastric ulcers?
Gastroscopy - 3m endoscope
4754
Why is a faecal occult blood test not reliable for diagnosing gastric ulcers?
False negatives
4755
How do you treat gastric ulcers?
Omeprazole (proton pump inhibitor) - Buffered - Enteric coated - Plain EGGUS requires higher doses
4756
Give some clinical signs of colic in order of increasing severity
``` Flank watching Lying down Pawing the ground Rolling Repeatedly getting up and down Violent thrashing around ```
4757
Give the different classifications of colic
``` Spasmodic Impactions Gas distension Obstructions (simple/ strangulating) Non-strangulating infarction Inflammation (enteritis/ colitis) Idiopathic ```
4758
How do severe cases of colic lead to shock?
Loss of vascular supply to mucosa Absorption of endotoxins into the circulation Systemic inflammatory response system (SIRS)
4759
What percentage of colic cases require surgery?
7%
4760
What initial advice should you give to an owner of a horse with suspected colic?
Put horse in a well bedded stable Remove anything it could injure itself on (buckets, feed etc) Let horse roll if it wants to A short period (10 mins) of walking exercise is fine but nothing longer before seeing a vet
4761
Which sedative should you give to a horse with colic when examining it?
``` Xylazine iv (200mg for a 500kg horse) Also gives analgesia ```
4762
Which queens should you ask a horse owner when investigating colic?
Which signs were observed? When did these start/ when was the horse last normal? Feed intake and faecal output over last 24 hours Any diarrhoea? History of equine grass sickness on premises?
4763
Which structures are identifiable during a rectal palpation?
``` Pelvic flexure Caecum Spleen Nephrosplenic space Small (descending) colon Inguinal rings ```
4764
What are some common findings when doing a rectal exam to investigate colic?
``` Distended SI Pelvic flexure impaction Left dorsal displacement Right dorsal displacement Large colon torsion Caecal impaction Small colon impaction ```
4765
What sized needle should you use when doing an abdominocentesis?
18g, 1.5 inch
4766
What is the appearance of normal peritoneal fluid?
Clear, straw-coloured
4767
Regarding peritoneal fluid, what are the normal values for: Total protein WBCC Lactate
Total protein:
4768
What is the normal packed cell volume of a horse?
35-45%
4769
What is the normal value for systemic total protein?
60-70g/L
4770
Which diagnostic tests should you do when investigating colic?
``` Haematology (systemic lactate, WBC, systemic TP) Rectal exam Abdominocentesis Nasogastric intubation Ultrasound ```
4771
What is the most common cause of colic in the foal?
Meconium impaction
4772
What is the medical term for equine grass sickness?
Equine dysautonomia
4773
What is the suspected cause of equine grass sickness?
Clostridium botulinum type C (exists in soil) Acute, subacute, and chronic forms Affects autonomic nervous system -> reduced GI motility Causes a paralytic ileus (obstruction of ileum) Patchy sweating, tachycardia Fatal
4774
What are the functions of the upper airways?
Channel for conveying airflow to and from lung Filtering and conditioning of inspired air Protection of lower airway from aspiration Olfaction Phonation Swallowing Thermoregulation
4775
Why is a normal upper airway so critical in a horse in particular?
Because the horse is an obligate nasal breather
4776
What is the tidal volume of a horse at rest?
5L
4777
What is meant by tidal volume?
Lung volume, representing the normal volume of air displaced between normal inhalation and exhalation
4778
What is the minute ventilation of a horse at rest and during exercise?
Rest: 75L Exercise: 1500L (20x increase)
4779
How do you work out minute ventilation?
Tidal volume x resp rate
4780
Give some clinical signs of upper airway disease
Nasal discharge Respiratory distress Exercise intolerance Noise at exercise
4781
When investigating URT disease, what should you look out for regarding nasal discharge?
``` Is it unilateral/bilateral? Chronicity Nature of discharge (blood/purulent/serous/food material) Recent head trauma? Recent URT infection? Is it associated with exercise? Any cough/ resp noise? Any facial swelling? Any response to treatment? ```
4782
When investigating URT disease, what should you look out for regarding respiratory noise?
When does it occur (rest/ exercise?) If it occurs at exercise, what pace does it occur at? Is the noise inspiratory/ expiratory/ both? What does it sound like? (Whistle, roar, gurgle, snoring) Continuous/ intermittent? If at exercise, does the horse stop/ slow down when it occurs? Does the noise disappear once the horse's speed reduces? Does the noise limit the horse's performance? Does the horse recover normally after exercise?
4783
When doing a clinical exam of the head, what should you look for?
``` Symmetry Nasal/ocular discharge Airflow from both nostrils Percussion of sinuses Palpation of larynx Evidence of previous surgical scars ```
4784
In RLN (recurrent laryngeal neuropathy- roaring), which Cricoarytenoideus dorsalis muscle is atrophied?
Left
4785
How can you determine whether a noise made at exercise is made during inspiration or expiration?
Expiration occurs as the leading leg hits the ground at canter and gallop
4786
Is 'roaring' heard during inspiration or expiration?
Inspiration
4787
Does dorsal displacement of the soft palate causes respiratory noises during inspiration or expiration?
Both: Expiration= loud Inspiration= soft gurgling
4788
Give some causes of abnormal respiratory noises heard at exercise
``` RLN (recurrent laryngeal neuropathy) DDSP Epiglottic entrapment Subepiglottic cyst Epiglottic retroversion 4-BAD (fourth branchial arch defect) Alar fold collapse/ nasal paralysis ADAF (axial deviation of the aryepiglottic folds) ```
4789
Which structures you examine with an endoscopy when investigating abnormal respiratory noises?
``` Nasal passages Sinus drainage angles Ethmoturbinates Nasopharynx Larynx Gutteral pouches ```
4790
What is the only way of identifying causes of URT obstruction that only occur at exercise?
``` Exercise endoscopy (High speed treadmill endoscopy= gold standard Can also use dynamic respiratory endoscope-attaches to bridle) ```
4791
How can you tell if a nasal obstruction is present above or below the nasal septum?
Rostral to nasal septum=unilateral discharge | Above nasal septum=bilateral discharge
4792
When doing radiography, the latero-lateral view is good for assessing which structures?
Paranasal sinuses, gutteral pouches and pharynx
4793
When doing radiography, lateral oblique views are good for assessing which structures?
Peri-apical regions of the premolars and molars (prevents superimposition)
4794
When doing radiography, the dorso-ventral view is good for assessing which structures?
Paranasal sinuses, nasal septum and teeth | Helps to decode of lesions are unilateral or bilateral
4795
Why might you perform a sinoscopy?
Investigate suspected paranasal sinus disease Obtain material for biopsy Treatment
4796
Which diagnostic techniques might you use to investigate suspected masses?
MRI | CT scan
4797
What is scintigraphy?
Radio isotopes are administered IV | The emitted radiation is measured by external detectors to produce 2D images
4798
When might you use scintigraphy?
Investigation of orthopaedic disease (eg fracture identification) Suspected TMJ disease Identification of damaged tooth Differentiation between primary and secondary sinusitis
4799
How can you investigate alar folds collapse?
Temporary suture across bridge of nose, if resolves, alar folds collapse is cause of problem
4800
Which bone separates the left and right nasal passages?
Nasal septum and vomer bone
4801
The nasal passages are divided into which 3 sections?
Dorsal, middle, ventral meatus
4802
What are the clinical signs of a problem with the nasal passages?
``` Nasal discharge Halitosis Abnormal respiratory noise Coughing Facial distortion Head shaking ```
4803
How can you diagnose problems with the nasal passages?
Radiography Ultrasound CT scan
4804
What is wry nose?
Congenital shortening of maxilla, nasal and vomer bones Causes laterally deviated rostral maxilla and associated nasal septum deviation Nasal obstruction Usually accompanied by malocclusion of the teeth
4805
Give some causes of disease in the nasal passages
``` Trauma Wry nose Deviation or thickening of the nasal septum Neoplasia (carcinoma) Progressive ethmoidal haematoma Fungal infection ```
4806
When placing an nasogastric tube, which meatus should it pass through?
Ventral (less likely to damage ethmoturbinates) | Use lubricant on end of tube, don't force it when you hit resistance
4807
What is an ethmoid haematoma?
Encapsulated non-neoplastic mass Grows into the nasal passages/paranasal sinuses Unknown aetiology
4808
What are the clinical signs of an ethmoid haematoma?
Mild intermittent unilateral epistaxis Occasionally abnormal resp noise at exercise +/- bad smell
4809
How can you diagnose an ethmoid haematoma?
Endoscopy +/- radiography | CT scan
4810
How do you treat an ethmoid haematoma?
Lesions in the nasal passages can be treated with intra-lesional formalin (causes aggressive necrosis of haematoma), however there is potential damage to sinus lining Laser removal Surgical removal Recurrence common
4811
What are the clinical signs of fungal rhinitis (nasal aspergillosis)? How do you diagnose and treat it?
Unilateral purulent/ occasionally haemorrhagic nasal discharge Foul smell Occasionally nasal stertor Diagnosis: endoscopy ``` Treatment: removal of fungal plaques and necrotic bone Topical treatment (nystatin powder) ```
4812
Name the seven pairs of paranasal sinuses
``` Rostral maxillary Caudal maxillary Frontal Dorsal conchal Ventral conchal Sphenopalatine Ethmoid ```
4813
How does drainage of sinuses occur?
Gravity and mucociliary action
4814
Where do the other sinuses (apart from rostral maxillary and ventral conchal sinuses) drain?
Into the caudal maxillary sinus -> Middle meatus via the nasomaxillary aperture
4815
What are the clinical signs of paranasal sinus disease?
Unilateral/bilateral nasal discharge (serous/purulent/mucopurulent/ occasionally haemorrhagic) +/- facial swelling +/- decreased nasal airflow (depending on amount of secondary oedema)
4816
Fluid lines within a sinus on a radiograph indicate what?
Sinusitis
4817
What is the difference between primary and secondary sinusitis?
Primary: usually results from previous resp tract infection, most commonly infection by streptococcus spp Secondary: to bother condition, primarily dental disease die to the proximity of the alveolar bone to the maxillary sinuses (08, 09, 10, 11)
4818
How do you treat primary sinusitis?
Rule out strep equi var equi (strangles) Place on antibiotics eg trimethoprim sulphonamides for 7-14 days Feed from the ground to encourage drainage Dust-free management Turnout as much as possible
4819
Which structure may obstruct the drainage angle of the ventral conchal sinus?
Maxillary septal bulla
4820
How may you surgically approach the paranasal sinuses?
Trephination or bone flap
4821
How do you treat sinusitis that is secondary to peri-apical tooth infection?
Remove affected tooth | Flush sinuses
4822
How do you treat sinusitis that is secondary to a facial fracture?
Remove/stabilise bone fragments | Flush sinuses
4823
Give some clinical signs associated with paranasal sinus cysts
Facial swelling Reduced nasal airflow Nasal discharge Nasal stertor
4824
How do you treat a paranasal sinus cyst?
Surgical removal
4825
What is suturitis?
Periostitis of the suture lines between the nasal and frontal bones Bilateral firm non-painful swellings in the nasofrontal region Usually regress with time
4826
What are the two main functions of the pharynx?
Deliver air from the nasal cavity to the larynx | Provides a pathway for food from the oral cavity to the oesophagus
4827
What separates the nasopharynx from the oropharynx?
Soft palate
4828
Why does the pharynx have the potential to collapse during exercise?
Lacks rigid support by bone/cartilage
4829
How does the pharynx retain stability?
Coordinated neuromuscular function
4830
Which nerves innervate the pharynx?
Mandibular branch of trigeminal Pharyngeal branch of vagus Hypoglossal Cervical nerves
4831
What are the main functions of the larynx?
Breathing (communication between pharynx and trachea) Protect lower airway (prevent inhalation of food during swallowing) Phonation/ vocalisation
4832
Which cartilages make up the larynx?
Cricoid cartilage Thyroid cartilage Epiglottis Paired arytenoid cartilages
4833
Which muscle is the principle abductor of the glottis?
Cricoarytenoideus dorsalis
4834
Which muscle is the principle adductor of the glottis?
Cricoarytenoidalis lateralis
4835
When does the glottis open and close?
Open: exercise Close: swallowing
4836
Describe the slap test
Used to diagnose left recurrent laryngeal neuropathy (roaring) Involves slapping one hemithorax to cause a reflex adduction of the muscular process of the arytenoid cartilage on the opposite side
4837
Which diagnostic techniques can be used to examine the larynx and pharynx?
Endoscopy- exercise and at rest Radiography Ultrasound
4838
Give some clinical signs associated with problems with the pharynx
``` Poor performance Respiratory noise Dysphagia (difficulty swallowing) Nasal discharge Coughing Respiratory distress ```
4839
Give some diseases associated with the pharynx
``` Cleft palate Pharyngeal lymphoid hyperplasia DDSP (dorsal displacement of soft palate, can be persistent or intermittent) Palatal instability Pharyngeal collapse Pharyngeal mass Foreign body ```
4840
When does intermittent dorsal displacement of the soft palate tend to occur? What happens?
Intense exercise | Soft palate displaces dorsally resulting in an expiratory obstruction
4841
Is intermittent or persistent dorsal displacement of the soft palate often secondary to other disease?
Persistent | Eg epiglottic entrapment, sub-epiglottic ulcer, sub-epiglottic cyst
4842
Give some clinical signs of dorsal displacement of the soft palate
Exercise intolerance Gurgling/vibrating noise Rider reports 'choking/swallowing its tongue'
4843
How can you diagnose DDSP (dorsal displacement of soft palate)?
Endoscopy: resting (limited value) and during exercise (gold standard)
4844
What is the function of thyrohyoideus?
Draws pharynx and larynx rostrally
4845
What is a 'tie-back' procedure?
Operation to resolve roaring | Arytenoid cartilage is pulled to the side and sutured to keep it from interfering with airflow
4846
What causes intermittent dorsal displacement of soft palate (IDDSP)?
Neuromuscular dysfunction: - Pharyngeal branch of vagus nerve/Hypoglossal - Thyrohyoideus - Alteration in laryngohyoid position - Inflammation
4847
Which conservative treatment could you use to treat intermittent dorsal displacement of soft palate (IDDSP)?
Get horses fit Change tack Treat inflammatory conditions of the pharynx and gutteral pouch Try throat support device?
4848
How can you surgically treat dorsal displacement of the soft palate?
Staphylectomy: partial soft palate resection Myectomy: removal of some of the extrinsic muscles of the larynx, reduced caudal retraction of the larynx Induction of palatal fibrosis: thermal/laser cautery, stiffens soft palate Tie forward: BEST, sutures placed between basihyoid bone and thyroid cartilage, positions larynx more rostrally and dorsally
4849
How would you identify a foal with cleft palate?
Milk at nostril
4850
What clinical signs are seen with laryngeal problems?
``` Respiratory noise Poor performance Dysphagia Coughing Respiratory distress ```
4851
Explain recurrent laryngeal neuropathy
Common, large breeds Unilateral paralysis of the left arytenoid cartilage Progressive loss of myelinated nerve fibres in the left recurrent laryngeal nerve Atrophy of cricoarytenoidalis dorsalis muscle Loss of abductor and adductor function
4852
How do you diagnose RLN (recurrent laryngeal neuropathy)?
Abnormal inspiratory noise at exercise - roaring Poor performance Clinical exam: +/- atrophy of CAD, negative result on slap test Endoscopy at rest: asses synchrony of movement, ability to achieve and maintain full abduction (grade 1-4: Havemeyer scale) Dynamic endoscopy is gold standard to asses degree of collapse during exercise
4853
Describe the 4 grades of the Havemeyer scale when grading RLN (recurrent laryngeal neuropathy)
I: all arytenoid cartilage movements are synchronous and symmetrical. Full arytenoid abduction can be achieved and maintained. II: arytenoid cartilage movements are asynchronous but full abduction can be achieved and maintained (sub-grades: 1.Transient 2.Permanent) III. arytenoid cartilage movements are asynchronous and/or asymmetric. Full arytenoid abduction cannot be achieved and maintained (1.Occasions of symmetrical abduction 2.Obvious asymmetry 3.Marked but not total asymmetry) IV. Complete immobility of the arytenoid cartilage and vocal fold
4854
How can you treat RLN (recurrent laryngeal neuropathy)?
Ventriculectomy | Laryngoplasty ('tie back')
4855
Describe a ventriculectomy procedure
Used to treat RLN (recurrent laryngeal neuropathy) 'Hob day' procedure Roaring burr used to every left or both ventricles, which are then excised +/- vocal cord removed at same time
4856
Describe a 'tie-back' procedure
Used to treat RLN (recurrent laryngeal neuropathy) Suture placed between dorsocaudal edge of cricoid cartilage and muscular process of arytenoid cartilage Mimics the action of CAD (Cricoarytenoideus dorsalis) Results in permanent abduction of left arytenoid cartilage
4857
Give some complications of tie-back procedures
``` Failure Dysphagia Aspiration Persistent cough Infection ```
4858
Give some causes of laryngeal paralysis (besides RLN)
Gutteral pouch disease Peripheral neuropathy (eg liver disease) Organophosphate poisoning
4859
Fourth branchial arch arch defect (4BAD) affects which side of the larynx?
Right side
4860
Explain fourth branchial arch defect
Variable development of the right laryngeal cartilage Right-sided asymmetry Rostral displacement of palatopharyngeal arch Variable ability to abduct right arytenoid cartilage
4861
What is vocal cord collapse (VCC) associated with?
ADAF | Axial deviation of aryepiglottic folds
4862
Describe arytenoid chondritis
Mucosal ulceration Infection of arytenoid cartilage Progressive Respiratory obstruction (younger TB, older mares)
4863
What are the gutteral pouches?
Air-filled mucosa-lined outpouchings of the auditory tubes connecting the nasopharynx to the middle ear Present in horses but no other domestic species Paired 350ml in volume
4864
Which structures border the gutteral pouches?
Dorsal: base of skull, first cervical vertebra, tympanic bulla, auditory meatus Medial: median septum, rectus and longus capitis muscles Ventral: nasopharynx, retropharyngeal lymph nodes Lateral: parotid and mandibular salivary glands, Pterygoid muscles
4865
How are gutteral pouches separated?
Separated into a medial and lateral compartment by the stylohyoid bone Medial is bigger than lateral
4866
Where do gutteral pouches empty?
Nasopharynx via a funnel-shaped orifice that has a fibrocartilage flap
4867
Internal and external carotid arteries supply which compartment of gutteral pouches?
Internal: medial compartment External: lateral compartment
4868
What are the clinical signs of gutteral pouch disease?
``` Epistaxis Swelling/dyspnoea Nasal discharge Nerve dysfunction -dysphagia -laryngeal paralysis -Horner's syndrome (constructed pupil) -facial asymmetry ```
4869
Give some diseases associated with gutteral pouches
Mycosis Empyema/chondroids Tympany Otitis interna/media Stylohyoid bone: temporohyoid osteopathy, fracture of petrous temporal/basisphenoid Rupture of longus capitus 'strap' muscle Neoplasia/cysts/foreign bodies
4870
Describe gutteral pouch mycosis
Primary fungal plaque forms over vessels (most commonly internal carotid) Uncommon but potentially life-threatening
4871
What are the clinical signs of gutteral pouch mycosis?
Nasal discharge Epistaxis +/- nerve dysfunction: dysphagia, Horners (pupil constriction), laryngeal paralysis
4872
How do you diagnose gutteral pouch mycosis?
Endoscopy
4873
How do you treat gutteral pouch mycosis?
Surgical occlusion of affected artery: simple ligation (back flow from circle of Willis), or balloon catheterisation, or coil embolisation Medical management if no history of bleeding: antifungals
4874
Describe gutteral pouch empyema
Purulent material (chondroids) within one or both gutteral pouches Usually in young horses Aetiology: URT infection, irritant drugs
4875
What are the clinical signs of gutteral pouch empyema?
``` Intermittent nasal discharge Parotid swelling and pain Extended head carriage Respiratory noise at rest Difficulty eating and swallowing Occasionally pharyngeal and laryngeal paresis ```
4876
How do you diagnose gutteral pouch chondroids?
Radiography (increase radiodensity-whiteness- of gutteral pouches on lateral views Endoscopy (dorsal pharyngeal compression, purulent material in gutteral pouches)
4877
How do you treat chondroids?
Flushing of gutteral pouches using catheters inserted via sinus ostia (small openings connecting sinus to nasal pharynx) Endoscopic removal of chondroids Surgical flushing and removal of material
4878
Describe gutteral pouch tympany
``` Foals Usually unilateral Marked retropharyngeal swelling Clinical signs of: swelling, resp stridor, dysphagia Confirmed on radiography or endoscopy ```
4879
Describe temporohyoid osteoarthropathy
Progressive disease of the middle ear and bones of the temporohyoid joint (stylohyoid bone, squamous portion of temporal bone) Aetiology: Middle or inner ear infection
4880
What are the clinical signs of temporohyoid osteoarthropathy?
Early: head shaking, ear rubbing, behavioural chane Chronic: facial nerve paralysis, head tilt, ataxia, nystagmus (toward affected side)
4881
What are the 'strap' muscles?
Longus capitus Rectus capitus ventralis Rectus capitus lateralis
4882
Why may the 'strap' neck muscles rupture?
Trauma | Usually due to rearing and falling over backwards
4883
Which clinical signs are associated with rupture of the 'strap' muscles?
``` Profuse bilateral epistaxis Ataxia Head tilt Pharyngeal and tracheal compression and secondary upper airway obstruction ```
4884
How do you diagnose rupture of the neck 'strap' muscles?
Endoscopy: roof of pharynx collapsed, normal vessels, swollen muscle bellies Radiography: fluid lines within gutteral pouch
4885
What is the treatment for rupture of the neck 'strap' muscles?
Stall rest Dependent on degree of concurrent brain trauma or skull fracture Anti-inflammatories Supportive care
4886
When is a tracheotomy carried out?
Emergency bypass of URT obstruction Route for intubation Rest the URT Bypass inoperable URT obstruction
4887
How would you perform an emergency tracheotomy?
Clip a 20 x 10cm area on ventral midline at junction between middle and upper third of neck Palpate paired sternothyrohyoideus muscles and tracheal rings Give 10ml LA (eg mepivacaine) into skin and underlying tissues Aseptically prepare site Make a 6-8cm incision on ventral midline of neck Palpate the two tracheal rings in the centre of the incision Make a stab incision between the two rings Extend the incision for 1-2cm each side of the midline Insert tracheotomy tube Secure in place
4888
Give some differential diagnoses for dysphagia
``` Oesophageal obstruction Retropharyngeal abscess (eg strangles) Retropharyngeal mass (neoplasias, granuloma) Pharyngeal foreign body Gutteral pouch mycosis Equine grass sickness URT infection ```
4889
Onchocerca cervicalis are found where?
Nuchal ligament | nematode
4890
How big are pinworms?
2-13mm
4891
What is the proper name for pinworm?
Oxyuris equi
4892
What is urticaria?
Raised itchy rash | Wheals, oedema and pruritus
4893
Sweet itch is caused by what? | Where on the horse is it seen?
Culicoides spp | Dorsal surface of horse: tail, mane, back
4894
What does atopy mean?
Hyperallergic
4895
How do you diagnose atopy?
Intradermal skin testing
4896
What is the difference between scaling and crusting?
``` Scaling= dry, grey Crusting= yellow, red, brown, wet/damp ```
4897
What is the difference between erosion and ulceration?
Erosion is superficial (partial loss of epithelial or mucosal surface that heals by resolution) Ulceration is deeper (full thickness loss of epithelial or mucosal surface which heals by repair ie replacement with fibrous tissue)
4898
Describe pemphigus foliaceus
``` Rare, autoimmune, horse makes antibodies against its own skin Severe crusting No age or sex predilection Dx: skin biopsy Tx: immunosuppressive drugs Prognosis: guarded ```
4899
Viral papillomas are seen where?
Muzzle, face, pinna, inguinal area
4900
Describe dermatophilosis congolensis
Gram +, facultative anaerobe, branching filaments on histology Favourable conditions= skin trauma, wet skin Thick, parakeratotic crusts (continuous epidermal invasion) Tx: topical (mild cases), systemic antimicrobials (severe cases)
4901
Bacterial folliculitis is caused by what?
Staphylococcus and streptococcus
4902
Give an antifungal used to treat ringworm?
Miconazole
4903
Describe leukocytoclastic vasculitis
Common, affects non-pigmented areas on distal limb Results from deposition of immune complexes at vessel wall Painful Dx: skin biopsy Tx: corticosteroids, avoid exposure to light
4904
Describe pastern dermatitis
'Greasy heel' syndrome Very common Caused by chronic wetting of skin on distal heel Winter, white limbs
4905
What are warbles?
Larval stages of Hypoderma bovis and lineatum, appear as nodule with a central pore (larvae inside) Neck and trunk Often painful Tx: enlargement of pore to remove central grub
4906
What is an atheroma?
Degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue Leads to restriction of circulation -> thrombosis
4907
What types of skin tumours are present in horses?
Sarcoids Melanoma Squamous cell carcinoma Mast cell tumour
4908
Describe sarcoids
Most common skin tumour in horses Tumour of fibroblasts Bovine papillomavirus 1 and 2 are most likely cause 6 clinical presentations: occult, verrucous, nodular, fibroblastic, mixed, malignant Dx: biopsy Tx: surgery, immune therapy, cytotoxics,
4909
Where are melanomas usually seen?
Perineum, tail head (near anus), parotid region
4910
How do you treat a melanoma?
Surgical excision, immunotherapy
4911
Where are squamous cell carcinomas usually seen?
Poorly pigmented animals | External genitalia, eyes
4912
Where are mast cell rumours found?
Head Solitary Males
4913
What clinical signs are associated with lymphosarcoma and other disseminated neoplasias?
``` Fever Weight loss Peritonitis Pleural effusion Abdominal distension Intra-abdominal mass palpable per rectum Hypercalcaemia/haemolysis/ cachexia of malignancy ```
4914
Give the 3 major clinical signs of lower respiratory tract disease in a horse
Cough Bilateral nasal discharge Tachypnoea/dyspnoea

Year 3 (28 decks)

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