Exotics and wild life Flashcards
Test one 5%
How the basic anatomy varies between species ?
Variation of avian species is easily observed in
- length of bones forelimbs / hindlimbs
- crop size eg diet
- choanal slit structure
- length of trachea
Identify and understand the basic external anatomy of the avian head ?
(Identify 1-7)
‘The external anatomy of a birds’ head
- Cere
- Rhinotheca
- Tomia
- the sharp edge of the beak - Gnathotheca
- Rictus
- extremely important where we can observe food build up. - Crest
- Ear covert
- Observing inside the mouth of a bird is an important step during an avian clinical exam - but why ?
- Describe how species may vary ?
Avian clinical exam
Oropharanx what to look for
- observe the choanal slit
- the choanal slit directly communicates with the nares and frontal sinus
- ideal location for sampling or to observe fluid accumulation
additional changes in the specific structure of the choanal slit can relfect disease ( changes in structure, toothed, massive etc).
Oropharanx and species variation
- Toungue and choanal slit can be highly variable between different species
- Tongue hard and rigid in predators, highly prehensile parrots, toothed in geese
Identify the glottis and trachea in this diagram ?
Identification of structures
Glottis (Green)
- opening to the trachea
(Purple)
- opening to the oesophagus
- important to understand how to administer fluids.
Describe the wing structure variation in birds, and the three areas of feather attachment ?
The forelimb - wings
The forelimbs - wings
- the bone structure of wings (even if not used kiwis) remains the same
- the only change between species is in the length of bones
- short humerus, hummingbird
Three areas of feather attachment and their purposes.
Primary
- Come off the phalanges and carpus
- primary lift and power (ENGINE).
- when wing clipping cut first five primaries
Secondary
- come off the ulna
- breaks and steering
Tertiary
- come off the humerus
filling the gap between the body wall and elbow
Coverts
- Second row over each region to cover the feather shafts and streamling the body
What is the Alula in avian species ?
Alula
- equivalent to slats on an aircraft
- can be used to increase turbulance and slow the bird.
Describe how the avian hindlimb is unique, and specific variations between species ?
Avian hind leg
The unique structures of the avian hind limb
- Synsacrum, the hip and sacrum are fused
- femur is typically hidden under the wing
- Fused tibiotarsus, fusion of proximal end of the tarsus with the tibia
- majority of species have four phalanges
Species variation of the hind leg in birds
- there is considerable variation in the length of the femur or tarsus
Identify which species crops a,b, c, d and e belong too ?
Crop
A
- slight dilation
- probable carniovre or ratite
B - granivore such as a budgie / parrot
C - omnivore eg peafowl, magpie
D - Bilobed pigeon
E - Distal dilation duck / cockatoo
Describe the crop and its importance in birds ?
The crop
The crop is a diverticulum of the oesophagus ( a real or potential space).
- a cranial/ cervical portion in the neck running alongside the jugular vein and trachea, the distal portion may or may not be dilated.
- leads to the proventriculus (real stomache)
huge species variation in size, shape and function.
Ducks - distal widening only
Pigeons - well developed / bilobed
Ratites - straight to the proventriculus no dilation
Describe how you could obtain a body condition score of a avian patient ?
Palpation of the keel
- coversmost of the ventral body
- primarily a muscle attachment to the superficial and deep pectoral muscles , attach to the proximal end of the humerus and pull the wing up and down
The keel is important in a clinical situation as it provides a valuable tool for asssessing body condition.
Also covers the majority of the midline body so provides the ideal place for IM injections as there is litle risk to the delicate internal structures of the bird.
Identify the muscles which attach to the keel ?
The keel
pectoralis muscle
Supracoracoideus muscle
Furcula - wishbone, fused clavicle
Coracoid
- fracture of the coracoid may present as a bird unable to fly, but no asymetry / wing droop observed.
What is the most important step in an avian clinical examination ?
History
Possible the hardest part of any consult, getting the information you need while politely ignoring the information they think you need ?
- may be difficult to obtain in a wild bird (typically unknown)
- patient history and problem history
- utilise open ended questions eg what did he eat this morning ?
- obtain information on the backgraound diet, housing, pet interactions, family interactions
- solitary or communal bird
- husbandry varies greatly between species and is often poorly undestood by owners
- History must include = origin, repro, diet and previous issues etc
A good history will assist you in your physical exam
Identify which bird is abnormal and why ?
The bird on the left is healthy.
Birds in health have a concave abdomen
- avian species have a single coelomic cavity (no diaphragm)
- single potential sapce, so changes in any area can be reflected with changes in shape / size of the coelom (readily palpable)
Best to know normal.
What are the three major components of your avian distance exam ?
Avian distance exam
While you are collecting a history observe the unhandled bird / birds.
The three major aspects to consider are;
1. The enclosure
2. Faeces
3. The patient
(healthy droppings pictured below)
What can an avian enclosure tell us ?
The avian enclosure.
What can it tell us, considering most pet birds arrive in their original enclosure
- beware excessively clean cages or carrier cages (wildlife, breeders)
- if they arrive in a different cage ask for a picture of the home cage
- is the cage of a suitable size
- is it designed well
- is it easy to clean
- what materials is it made of
- substrate / floor conditions
During our distant avian exam what can the patient tell us ?
Distant avian exam - the patient
Remeber the majority of species are prey items and they know it
- Masking phenomenon don’t want to be eaten well don’t look sick
- Birds will utilise stored energy, catabolise their protein stores and waste away while trying to appear healthy.
So what might the clinician see
- alertness a healthy bird will be watching you, watching them
- respiratory effort, tail bobbing, chest movements or open mouth breathing
- apetite and thirst
- coordination
- sick bird syndrome, fluffed feathers
During the distant avian exam, what could the droppings potentially tell us about our patient ?
The droppings
In health
- three simple parts
- faeces = food waste (well formed)
- urates = protein waste, processed in the liver excreted via the kidneys (yellow biliverdin)
- urine =liquid waste flushed out via the ureters
- faeces will greatly vary between species depending on health, age, gender and diet
Diarrhoea
- will appear as an unformed faeces component
- watery component (top left = overnight, Centre = not eating, top right = cranberries and bottom typical of a stress defaecation.
Describe the important features of an avian clinical exam ?
Avian Clinical exam
- Handling
- handling use different approaches depending on your patient
- aim for the minimum amount of restraint without looking like a fool
- weighing perch, hand towels, GA may save dramas - Always obtain the birds weight
- weighing perch
- need a starting point for medication doses rates and monitoring changes - Identify individuals sex
- monomorphic, dimorphic species, or DNA / surgical
- important to identify gender specific diseases
- also crucial for perception of knowledge (eclectus) - TPR is unreliable
- temps 40-41, pulse 200-800 and breaths 5-60 - What the clinicain needs to assess
- palpation of the crop and abdomen, which should be concave
- observe around vent
- integument (dermatitis no oozing pus no lysozomal enzyme).
- ceres
Use your history, clinical exam and faeces sample to define your problem.
Identify and understand the basic diagnostic procedures that can be used in avian patients ?
Techniques and specific tricks of the trade ?
Understand and interpretation of results ?
Avian diagnostic testing
Faecal test / fresh smears / stains
- most important diagnostic in avian species; fresh smear first, stained smear and faecal floatation if justified
- fresh faecals first, can always follow on with other stains etc
- minimal sample so there is a thin spread
- allows evaluation of fragile motile organisms that won’t stain
- faecal flotation rarely used except for flock screening / quantitative
Microbiology
- granivores in health mostly gram+ve bacilli, yeast may alo stain gram+ve
- sick bird = monoculture
- gram negative red counterstain
- microbiology, allows appropriate selection of antibiotics based on culture and sensitivity
- gram stain essential in avian/exotic medicine
- crucial relative sizes, contrast
Serology / haematology
- Body’s response to disease
- eryhtrocytes are nucleated
- thrombocytes
- heterophils
Biochemistry
- which organs are affected
Cytology
- Diff Quick
Diagnostic imaging
Endoscopy
Describe sick bird syndrome ?
Sick bird syndrome SBL
Birds present all the same when they are sick
- prey species which are skilled at masking
- until they reach a point when they can mask no longer, and become to ill to hide their illness
This makes diagnostic testing critical for our avian patients.
Identify this test, and what the clinicain is looking for ?
Feather pluck test
- diagnosis for blood parasites
- leukocytozoans dark C formed within reactive white blood cells.
What stain is best utilised to identify cryptosporidium ?
Cryptosporidium - Modified Zhiel Nelson stain
What stain should be used to identify cytological pathology ?
Cytology assessed via Diff Quick
Cytological stain, not usually used for bacterial identification
- all bacteria will appear the same colour and yeasts stain inconsistently.
Describe some issues a clinician must consider when carrying out a blood sample in avian species ?
Blood sample issues avian species
Avian patient size
- most patients are small, yet most comprehensive tests require 0.5ml of blood.
- can only safely obtain 1% of body weight
- needle size selection is crucial
- to big = haematoma, too small may cause haemolysis
- 25-27 guage
Culture and sensitivity
- may take up 2-7 days to get results, which is too late for our patient
- medication may have to be based in the interum on an educated guess
- in house culture may be used to speed up the process
Over interpretation of results
- beware of haemolysis and lipaemia
- take care to treat your patient not the the result
- normal variation can occur in health eg young birds have a higher PCV and lower WCC
- artefacts
Describe the unique features of avian blood ?
Unique Avian Haematology
(similar haematology to mammals)
Unique features
Heterophils
- neutrophils which do not contain lysozymes, and this accounts for why birds do not have liquid pus
- Lymphocytes
- Eosinophils, highly granular
- Monocytes
- Basophils, dark coloured
Eryhthrocytes are nucleated
- polychromasia (variation in cell colour) is common
- shorter cell life so always turning over making polychromasia a regenerative feature common
- anaemia < 40% PCV
Thrombocytes - not platelets
Why must a total white blood cell count be carried out manually in avian species manually ?
Nucleated red blood cells which means 100% of avian cells will be automatically counted as white blood cells.
What is unique about the avian mechanism of clotting ?
Avian clotting
Birds have thrombocytes
and undergo the extrinsic clotting pathway involving the release of thromboplastin
- this means clotting is induced by tissue damage in avian species, as opposed to mammals where clotting is induced by cutting of vascular channels.
This is important for surgery in avian species
- clotting may be induced by crushing prior to cutting
Identify the cell types in this picture ?
Identify cell types
Blue = heterophil
red = lymphocyte
green = monocyte
Identify the following avian cell types ?
Identify the avian cell types
nucleated cells = eryhthrocytes
blue = thrombocyte
green = basophil
red = heterophil
Identify the avian cell types ?
Avian cell type identification
Dark green = heterophil
Yellow = reactive heterophil
Dark green = basophil
Blue = lymphocyte
Note basophils and eosinophils are commonly not present in a healthy avian blood sample.
- there presence almost always means pathology
- basophils, tissue damage, inflammation or immediate hypersensitivity
- eosinophils = tissue damage usually in avian patients not parasites.
Describe the main biochemical markers of hepatic disease in avian species ?
Avian hepatic disease : Biochemistry
Hepatic enzymes;
AST (Aspartate aminotransferase)
- avian specific
- rapidly incraeses with hepatic necrosis (3-5x impress), but will also elevate with muscle damage
- when combined with elevation with CK more likely to indicate muscle injury
GLDH
- found in hepatocyte mitochondria, provides evidence of hepatic death
Products of the avian liver
-** Bile acids, made in the liver and then recycled through hepatic circulation (high levels indicate they have not been removed from circulation)
- Cholersterol;** made in the liver from fats, carbs
What observations on biochemistry would indicate renal disease in birds ?
Avian renal disease
This is indicated through uric acid elevation
- made in the liver from protein waste
- sent to the kidneys for processing and excretion via the ureters
- water is reabsorbed at the cloaca and then excretion occurs as urates
Urea levels are insignificant in the bird
What are normal biochemical changes which are frequently observed with birds in breeding ?
Avian reproduction
Calcium
- breeding females mobilise calcium from bones for egg shell development
Cholesterol and triglycerides
- elevate transiently when the egg yolk is being produced
Total protein
- will elevate during egg production due to transportation of egg components (albumin)
Describe what biochemical changes should be observed to diagnose GIT disease, diabetes ?
Avian biochemistry
GIT disease
- typically observe changes in Na, CL and K
- amylase may become elevated with pancreatic disease
Glucose
- low levels starvation, spesis or an artefact from blood storage
- increased levels should be ignored unless extreme >33 consistently for the diagnoses of diabetes.
Describe the benefits and negatives of serology vrs PCR testing ?
Avian serology vrs PCR
PCR (DNA testing of pathogen)
- highly specific and sensitive
- for many purposes it is too sensitive, with false results occuring due to contamination, medication
- eg doxycycline inhibits chlamydia result 24hrs despite the bird having clinical signs
Serology (Immune system proteins, antibodies)
- levels influenced by host immune system eg immunosuppression
- antibodies are easier to detect
- good for flock screening
- low sample requirements, small volume of blood
- lower cost compared to PCR
Ideal is to combine PCR and serology
Describe the common techniques for radiography in the avian species, including views ?
Avian radiographs
(Quick GA is best technique)
Two standard views and one specialty
- VD
- Lateral
- H view
VD - is best to assess bone
Lateral is best to assess organ and spinal assessment, wings dorsal and cranial
H view - best to view coracoid
In birds what is an H view radiograph ?
H view radiagraph
H view - caudoventral-craniodorsal oblique
- basically a VD taken at a 45 degree angle
- allows seperation and highlighting of clavicle, coracoids and scapulas
- removes overlap for best exposure
- extremely important in performanace birds such as raptors.
What is SBL, and how dose it present ?
SBL - Sick bird look
There are limited ways in which a bird can express illness.
- masking avoid predation
- by the time they look sick thay are extremely sick
- owners often present bird to the vat late in disease due to masking, cost and hope it will get better.
Presentation
- sunken eyes
- mucoid saliva
- decreased capillary refill
- wrinkling, scaling or tenting of the skin
- decreased urinary out - put
What factor lead to SBL, and how can the Veternarian intervene ?
SBL - Sick bird look
Aim for a tentative diagnosis in a live patient (better then a confirmed diagnosis in a dead patient)
Interim supportive care can make the difference between the two outcomes.
What causes SBL
* dehydration
* hypothermia
* catabolism
* pain
* blood loss
Describe specific technique for correcting dehydration in an avian patient (routes of administration)?
Avian dehydration correction
1. Subcutaneous fluids
- often a first step in stabilisation as they can be given quickly to an unconscious bird
- inguinal region or over hips (juveniles)
- can save the veins
- note neonates do not tolerate well being flipped upside down
- NEVER GIVE IN THE CASE OF EMPHYSEMA
Crop lavage / oral fluids
- unsafe higher risk of aspiration for recumbant or seizuring patients
- often a good option for recovering birds / birds which have turned the corner
- utilse the largest tube available as it reduces the risk of placement in the trachea / won’t fit
- dosen’t require GA
IV fluids
- typical rate 100ml/kg/day
- limited veins available, all veins are fragile, haematomas occur easily, do everything slowly
- right jugular (larger in most species)
- medial metartarsal
- cutaneous ulnar veins
Interosseus fluids
- distal ulnar
- usually only useful for 3-4 days as the site becomes painful
Desribe the quantity of fluid used to correct dehydration in an avian patient ?
Correcting avian dehydration
(Crystalloids 2.5% glucose, 4.5% saline)
Assume all sick birds are atleast 5% dehydrated
- aim for 10% of body weight daily for three days
- follow by a reduction in fluid therapy to 5-7% daily
- consider higher dose in cases of ongoing loss such as diarrhea, polyuria
- it is reccomended to divide the daily amount into 2-3 doses.
Identify this avian technique ?
Interosseus fluids
Common site distal and proximal ulna
How would you recommend treating hypothermia in an avian patient ?
Birds hypothermia
This often kills birds long before the disease will - act fast
- feathers fluffed to trap body heat
- birds run hot 40-41
- lethargic and sleeping to conserve energy
- too weak to perch, often on the floor of cage
Treatment
Heat cages to 30-32 degress
- brooding enclosures
- vetarios
- hospital cage
- continually monitor for heat stress or further dehydration
What is going light and how can we correct this condition ?
Going light = catabolism
SBL burning energy to maintain ‘healthy’ appearance + fight disease
- reduced faeces
- poor body condition
- small urates
- monitor weight
Treatment
- ensue water and food is easily accessable
- offer high calorie faveroite foods
- crop lavage / Emeriads or hand rearing mix
- feeding tube / oesophagostomy tube
Oesophagostomy tube is easily placed but may require a cone to prevent avian interference.
How can we address respiratory compromise in an avian patient ?
Avian respiratory compromise
(Not typically part of SBL)
Clinical signs
- open mouth breathing
- increased respiratory effort
- audible respiration
- cyanosis
- tail bobbing collapse
Treatment
- supplementary oxygen
- many modern brooders
- simple bubble system
- in emergencys with tracheal obstructions, can use a small ET tube placed into caudal air sacs to by pass the obstruction
Describe what drugs are best utilised to treat pain in birds ?
Pain in birds
(sources of pain - acute = flight/fight, where as chronic pain more likly to display a withdrawal response).
Treatment
1. Remove the source of pain eg splint fractures, treat infections
2. NSAIDS Meloxicam 1.5mg/kg BID injectable or oral.
3. Opiods Tramadol, noting many opiods have a very short half life in birds.
Why are birds more resiliant in the face of blood loss ?
Avian haemorrhage
Birds are more tolerant of blood loss than mammals
- more efficient respiratory system
- increased capillary bed with skeletal muscle
(rapid extravascular fluid resorption to maintain vascular volume)
- ability to mobilise large numbers of immature erythrocytes
- no autonomic response to haemorrhage, so haemorrhagic shock is less likely
Treatment
- in most cases / mild - moderate fluid therapy
- warmth
In severe cases blood transfusion, use the most homologous sample available
eg galah to galah > cockatoo to galah > other parrot to galah
- transfusion reactions can occur with repeat infusions.
What differentials would you suspect on presentation of a bird with bilaterally symetrical feather loss ?
Differentials for bilaterally symetrical feather loss in birds
- moulting
- stuck in moult
- hormonal, hyperestrogenism
Describe the normal process of moulting in birds ?
Moulting
Feather loss is a normal part of moulting
- usually present bilaterally symetrical
- controlled by the thyroid gland and modulated by diurnal cycles and photoperiod
- occurs in health
- usually occur twice a year; spring pre-nuptial and autumn post nuptial
- while some species have no change in appearance in others dramatic plumage change
(exception some water fowl)
A bird presents with substantial bleeding from the tail (below), what should we do ?
Suspected broken feather quill
(Physically inspect bird its not always a broken bone or tissue trauma).
When a new feather forms in a follicle, the live tissue has a central artery and vein in order to supply nutrients to the growing feather.
- once the feather is fully developed, the blood vessels shrink hypertrophy, and dry up
- damage to the developing blood quill will cause copious bleeding as you have essentially severed an artery.
Treatment
- the best treatment is to pull out at the base, disrupting the blood supply.
What is stuck in moult caused by ?
How can we treat this condition ?
Stuck in moult
This common in canaries but may occur in other species
- typically indoor housed birds exposed to constant and excessive photoperiod and protein deficient diet
- birds continually look untidy, always loosing feathers as the moult process has no start or stop
Treatment
- Institute a distinct diurnal cycle and correct protein deficiency
- Dark room 8-12hrs a day
- treatment may intially trigger a profound moult warn owners.
Provide a list of differentials for feather loss in birds ?
Feather loss in birds
- behavioural
- predator avoidance, escape mechanism particularly in pigeons
- social, often seen at breeding time (forced to nest by mate
- stressed pet shop birds
- feather picked chicks as they are pushed by parents to leave the nest
- hormonal (hyperoestrogenism)
- self inflicted
- parasites (mites)
- circovirus
Identify and describe the treatment for the pictured pathology ?
Feather cyst
This is basically an ingrown feather
- often occurs due to surface trauma and may be genetic (canaries)
Treatment
- excise the cyst, but they will commonly recur.
Discuss how you can treat parasites on birds and their respective withholding periods ?
Infectious causes
(often over diagnosed by owners)
Did the parasite cause the damage or has the parasite overproliferated on a sick animal.
Parasites are commonly found on healthy indivduals
- lice, present in low numbers on most birds
- Mites (Cnemidocoptes) scaly face mite
- red mite, must treat the environment and the bird
Treament
Pyrethrins withhold 2weeks
Mectins withhold 28 days
Describe the presentation and treatment of common infectious causes of feather loss in birds ?
Infectious causes of feather loss
(bacterial / fungal)
Presentation
often non specific, focal infections (axillary dermatitis) or scattered diffuse disease.
- swollen feather follicle, folliculitis
Treatment
- swab, gram stain, culture and sensitivity
- provide systemic meds never topical
- topical meds can prevent thermoregulation in birds.
Describe the pathology, presentation, diagnoses of circovirus ?
Beak and feather (circovirus)
Pathology
- attacks rapidly dividing cells, new feather growth, bone marrow
- more common in juveniles
- all parrots (but less common in Sth American and cockateils
- has been seen to jump species barriers
- incubation can be short 3wks, but also may take years
- horizontal and vertical transmission suspected
Presentation
- weakness and lethargy
- dystrophic feathers and beak necrosis
- loss of primary feathers
- colour changes green to yellow, grey to red and blue to white
Diagnosis (test quill contents rather than whole blood)
- histopathology
- serology
- PCR very sensitive, may indicate exposure but not carry a current infection
Describe acute circovirus and its treatment ?
Acute circovirus (beak and feather)
- primarily affects black cockatoos and african greys
- uncommon
- sudden onset of weakness, lethargy in juveniles
- regenerative anaemia and pancytopaenia
- death within 24-48 hrs from liver necrosis.
Usually mass casualties
euthanasia is often the best option ethics wise
Describe the presentation of chronic circovirus and its treatment ?
Chronic circovirus (beak and feather)
Presentation
- usually juveniles
Cockatoos
- Classic form cockatoos only, dystrophic feathers and beak necrosis
- beak may be acutely painful (ethics)
- loss of feather down, beak and dark feet
Lorikeets
- loss of primary flight feathers and tail
- bilateral loss of outermost 3-4 primaries (lose ability to fly)
- feather colour changes
Treatment
- some lorikeets appear to recover but continue to shed
- most die within two years
- ethics consider pain (beak necrosis)
- best option is euthanasia
Describe the presentation of Polyomavirus and its pathology ?
Polyomavirus (french moult)
Pathology
- All parrots affected, some finches
- budgies mcaws, rarer in cockatoos
- usually observed at the start of the breeding season
- viraemic; rapid death, haemorrhagic pectoral muscles and internal bleeding
- liver necrosis
Presentation
- french moult
- often seen as massive increase in chick mortalities
Describe how you would diagnose and treat an out break of polyamvirus ?
Polyomarirus
(french moult + haemorrhagic pectoral muscles)
Diagnoses
- histopathology
- PCR (blood and cloaca
- viraemia in blood will caese long before faecal shed
Treatment
- sometimes spontaneous recovery in budgies
- stop breeding for a minimum of six months to stop the cycle
- other breeds rarely recover euthanasia.
Describe the steps a clinician should take with FDB ?
FDB Feather destructive behaviour
Plucking / picking/ chewing / barbering - components not seperate disease.
Multiple causes
- underlying pain irritation (fractures neoplasia, dermatitis etc)
- malnutrition, itchy, poor quality skin and brittle feathers
- psychological problems
The FDB plan
- start be a complete history
- followed by a thorough clinical exam
- address any underlying pain
- there is no test for the diagnosis of behavioural problems
- avoid e collars or sedatives unless there is physical damage to tissue - litle evidence to support there use.
- success is often reduced problem behaviour a complete cure is rare
What is the 80/20 rule and how can we use this to address FDB ?
FDB Feather destructive behaviour.
80/20 rule
- In the wild birds spend 80% of their time foraging and only 20% of their time resting or preening
- often in captivity this is reversed with birds spending 80% of their time resting / preening
- this contributes to feather destructive behaviour due to boredom / stress
Treatment
- reintroduce active foraging for foods
- baffle cages
- scattering foods
- multiple food dishes through out aviary
- covering food dishes
- pine cone parcels
- add toys to destroy, social interaction
Describe the common components of the avian respiratory system ?
Basic anatomy of the avian respiratory system
Head
- internal nares
- turbinates of the nasal cavity are for smell
- infraorbital sinuses (warming and humidification)
- glottis which opens into the wind pipe
Lungs
- paired
- no diaphragm
- non expanding ventral part is responsible for the majority of gas exchange
Air sacs
- Cervical air sac - thermoregulation and buoyancy
- interclavicular paired air sac
- anterior thoracic
- posterior thoracic
- abdominal air sac
What is unique about the avian trachea ?
The avian trachea
Longer and wider than in comparable mammals
- complete cartilage rings
- narrows cranial to caudal, interlocking broad and narrow cartilage rings
Syryinx
- bifurcation into the bronchi
- site of voice production
- common site for tracheal obstruction as it narrows even further
This severely limits our choice of ET tubes - never cuff a bird and inflate
Describe the unique features of avian air sac ?
Avian air sacs
- single cervicle air sac
- paired interclavicular air sac
- anterior thoracic pair
- posterior thoracic pair
- abdominal pair of air sac
- 3 air sac cranial to lung and 3 pairs caudal
The unique anatomy of an air sac
- poorly vascularised
- common sites of infection
- act primarily of bellows
Describe the respiratory pattern of birds ?
Avian respiratory pattern
(4 cycle respiration pattern)
There are multiple steps happening at once, constant uni-directional flow.
Inhalation
1. Primary - pulls air past lungs to posterior air sacs
2. Secondary - moves waste air into cranial air sacs
Expiration
1. Primary - moves air caudal air sacs into lungs
2. Secondary - moves waste air out of body
Describe how respiratory disease presents in avian species ?
Presentation of respiratory disease in avian patients
Upper respiratory tract
- sneezing
- staining of the feathers above nares
- sinus swelling
- ocular discharge
- matting or loss of periorbital feathers - from rubbing face on perches and wings
Tracheal disease
- usually an acute onset
- coughing (often the only time we see coughing in avian patients)
- open mouth breathing
- neck stretchingaudible respiratory signs
- distress
Lung and air sac disease
- Chronic onset
- increased respiratory effort
- mouth breathing
- tail bobbing
- sternal shift
- weight loss
Describe the pathogenesis and predisposing factors for sinusistis ?
Sinusitis
Hyperkeratosis of sinus mm - clearage mechanism inhibited.
Predisposing factors
- hypovitaminosis A from a poor diet
- infectious, chlamydiosis, mycoplasmas
- chemical irritants, ammonia
Identify this pathology and desribe its treatment ?
Sinusitis
Treatment
- parental vitamin A given as ADEC injectable
- nebulising, steam as a mucolytic and drugs as required
- nasal flushing - syringe in nares, invert bird and express (must be a conscious bird)
- surgical flushing
Identify this condition and your understanding of its pathology ?
Tracheal disease
Pathology
- functional extraluminal pressure - coracoid
- infection/ pox, trichomonas, aspergillosis
- - inhaled foreign body
Treatment
- Obstruction clear debris
- very difficult area to debride, very good blood supply
- acute onset, dyspnoea after coughing
In extreme situations create an alternate airway with an air sac catheter, good for 3-5 days
Identify and describe how to treat the following pathology ?
Air sac rupture
- typically traumatic but can be infectious (tissue damage)
- depends on location but usually a simple fix
- drain the air out with a small incision - end of a 18G needle in conscious birds
- rarely must be repeated
- avoid SC fluids in these birds
You observe a bird mouth breathing with increased respiratory effort and tail bobbing.
This makes suspiciuos of lung and air sac disease - write a differential list ?
Differential list
Lungs
- parenchymatous disease caused by a hypersensitivity in Mccaws
Air sacs
- primary air saculitis often aspergillous or chlamydia
- compression due to fluid build up - peritonitis, ascites
- masses - egg stuck, anaemia
To form a definitive diagnosis
- cbc
- biochem
- radiology
- direct endoscopy
Describe the pathology and diagnoses of Aspergillous
Aspergillous
Presentation
- plaques and granulomas in tissue, lung and air sacs
- occasionally seen outside the respiratory tract
Pathology - Its everywhere
- has species predilections ratites, raptors and african greys
- immunosuppression; poor diet, concurrent disease or overcrowding may make birds susceptable
- exposure high concentration at nesting site
- - warm humid environment encorages sporulation
Diagnoses
- plaques and granulomas in sinuses are pathonomonic
- leukocytosis with monocytosis and basophilia
Identify this pathology and describe its treatment ?
Aspergillous respiratory disease
(fungal)
Diagnoses
- plaques and granulomas
- leukocytosis, monocytosis and basophilia
- radiology, endoscopy
Treatment
- endoscopic debridement if singular plaque
- amphotericin B nebulizing
- itraconazole 6 months treatment expensive
Identify the most probable respiratory disease pictured, and how you would confirm your suspicions ?
Chlamydiosis
(Highly contagious disease)
Presentation - SBL
- Csx vary with strain and virulence
- respiratory mostly upper respiratory signs
- conjunctivitis / matting of periorbital feathers
- dyspnoea
- sneezing
- purulent nasal discharge
- sinus distension and saculitis
- insevere cases presents neurologically, tremors, torticollis
Definitive diagnoses
- GIT hepatic signs, diarrhoea, biliverdinuria (urates and urine)
- SBL fluffed up, anorexic
Describe the pathology underlying chlamydiosis
Transmission highly contagious, via inhalation, ingestion of aerolised drolets
- obligate intracellular bacteria g-ve
- infection may be latent and activated by stress
- think healthy at pet shop, with disease becomming activated with a change in environment
- short lived immunity
Shedding can start 72hrs after primary exposure and may shed for 7 days before csx develops.
Describe how you could make a definitive diagnosis and treat chlamydiosis in an avian patient ?
Chlamydiosis
Diagnosis
- safest to assume when classical signs present, diagnostics take too long
- PCR
- biopsy / cytology
- antibody detection on serology
- biochem (AST / CK)
- radiology very large spleen
- biliverdinuria
Treatment
Tetracyclines - inhibit chlamydia protein synthesis
remember intracellular bacteria so must be actively replicating to be effective
45 days duration of therapy
Define polyuria and polydipsia ?
Polydipsia is usually secondary to polyuria
Definitions
Polydipsia
- water intake in excess of double the daily maintenance requirement > 100ml/kg/day
Polyuria
- quantification is difficult but excessive urine output
- often presented as diaorrhea from clients
- subjective assessment by visual exam of droppings
What types of nephrons does the avian kidney contain ?
Avian kidney; two types of nephrons
Reptilian - no loop of Henle
reduced ability to concentrate urine
Mammalian nephron - contain a loop of Henle
Describe the physiology behind the production of urine in avian species ?
Physiology of urine production in birds
Plasma osmolarity
- controlled by complex interactions between the hypothalamus. pituiatry gland and kidney
- osmorereceptors and baroreceptors
Argine vasotocin
- avian equivalent of ADH, produced in the pituitary in response to increased osmolarity
- acts on kidneys to reduce blood flow and increase absorption of urine output
Cloaca
- this is where urine is concentrated
- backflushed from urodenum into coprodenum and then returns across the concentration gradient
Effective osmoregulation requires what physiological characters in avian patients ?
Avian; effective osmoregulation requirements
Sufficient functional nephrons
- decrease with nephritis, nephrosis or renal gout
Normal production and response to argine VT
- diabetes insipidus / neurogenic (pituitary failure)
- efficient cloacal reasorption
(decreased stress, enteritis
What is diabetes Mellitus and how dose it present in birds ?
Diabetes mellitus - hyperglycaemia
Avian diabets mellitus
- most common budgies, cockatiels and galahs
- glucagon ; insulin ratio 2-5 time higher than in mammals
- type one destruction of pancreatic islets
- type two obesity
- iatrogenic, administration of oestrogenics or corticosteroids which inhibit the effect of insulin
Describe the traditional control of glucose regulation ?
Glucose regulation
Blood glucose is regulated by interactions between
Insulin - anabolic hormone allows transfer of glucose into cells
Glucagon - catabolic hormone, stimulates gluconeogenesis, lipolysis and glyconeogenesis increasing blood glucose
Somatostatin - modulates glucagon and insulin
Describe how you would diagnose and treat diabetes in avian species ?
Avian diabetes mellitus
Diagnosis
- pu/pd, polyphagia and wt loss (but mostly lose protein so may still appear obese)
- persistent glucose >38-44 mmol/l
- A single reading is not diagnostic
Treatment
- management, lower blood glucose and restore glucose management
- determine and correct primary disease
- stabilise an unwell patient by providing fluids
- correct hyperglycaemia , insulin, good diet and wt loss
Kidney B = a diseased kidney
Describe how a bird would present when ill ill with PU/PD ?
PU/PD
Clinical signs
- fluffed and lethargic
- anorectic and increased thirst
- regurg / vomiting particularly if polydipsic
- persistent polyuria
- lameness or wing droop from articular gout in chronic illness (shifting lameness frequently seen)
Diagnosis
- Uric acid > 800umol/l
- elevated urea (but this is also caused by dehydration
- mild anaemia 30-37%
- radiographic renomegaly and / or minerlisation ( in health kidney sits between the head of the humerus and the acetabulum)
Treatment
- fluids
- antibiotics / antiinflammatories
- Colchicine - reduces UA and limits fibrosis
Identify this condition and the anatomical locations where it builds up in avian species ?
Gout
UA precipitating out of the blood when saturation levels are exceeded (>800 umol/l)
Accumulation;
Visceral gout
- acute renal insult, pericardium, myocardium and serosal surfaces usually die of heart failue
Articular gout
- slower, chronic renal failure, precipitates into cooler parts extremeties ?
Describe how we could diagnose and treat gout ?
GOUT - renal insult
Diagnosis
- articular gout; make an incision (tooth paste consistency) easy to identify crystals on a microscope slide
Treatment for gout
(Visceral gout usually only identified post mortem)
Cholicine, Allopurinol - reduce UA
analgesia (never use NSAIDS)
remove trophi, but be careful the bleed profusely.
Describe the common causes of heavy metal toxicity and its presentation ?
Heavy metal toxicity - Zinc and Lead
A very common condition
- in pet birds, cage wire, poorly designed toys and lead paint
- aviary birds galvanised wire mesh, the poorer the quality the higher the lead
Presentation
- PU/PD
- vomiting and diarrhea
- lead = haematuria and ataxia or seizures
Describe how you would diagnose and treat a heavy metal toxicity ?
Heavy metal toxicity / Zinc and Lead
Diagnoses
- PU/PD
- anaemia
- zinc on biochem Uric acids
- Blood lead
- radiographs (but be careful not all that shines is metal, hyperechoic compare to leg band)
Treatment
Chelation** CA EDTA**
- correct environment
- can wash mesh with vinegar to cause super oxidisation
- warm fluids, control vomiting
Identify each part of the avian female reproductive tract and their function ?
Avian female reproductive anatomy
Female
In the embryo there is two ovaries, but the left side preferentially develops
Functional regions of the female reproductive tract
Ovary - production and release of eggs
Infundibulum - site of fertilisation
Magnum - deposition of albumin
Isthmus - membrane is added
Uterus - shell produced + pigmentation
Vagina - transport egg to the out side
Describe the male avian reproductive tract ?
Male reproductive tract / avian
- two internal testicles
- usually creamy white in colour but can be black cockatoos, Aus parrots
- massive seasonal varitaion in testicular size.
Describe the development of the avian reproductive tract.
Sexual development in avian species
In birds sex is heavily controlled by the dose of a sex gene DMRT1
- single dose of DMRT1 = female
- double dose DMRT1 = male, two copise of the gene cause birds to develop as male
A male bird’s secondary sexual characteristics like showy plumage, singing voice, size and dancing ability are controlled by the Z chromosome
Males are homozygous ZZ
Females are heterozygous ZW
- female birds have a Z chromosone but it is prevented from producing testosterone via the inhibition of oestrogen
- oestrogen inghbits the gene which would usually trigger male characteristics
Identify this pathology and your recommended treatment ?
Testicular cell tumour
presentation
- change in cere colour male to female (male blue) budgies
- chronic weight loss and abdominal distension
- unilateral paresis of leg due to the sciatic nerve
Treatment
- GNRH agonist desrelorin, short term
- orchidectomy in cases with no metastatic disease
Identify this pathology and your recomended treatment ?
Phallus prolapse
Ratites and ducks have large phallic organs
- normally retract after use
- ‘overuse’ may lead to a failure in the ability to retract
- exposure may result in injury or necrosis
Treatment
- early cases may be managed with a purse string suture (never close)
- may also require resection of damaged tissue
Describe the pathophysiology and presentation of salpingitis / metritis ?
Salpingitis - inflammation of the fallopian tube
Metritis - uterine infection
Pathology; Primary infections are uncommon in domestic situations
There are a number of predisposing factors
- excessive egg laying / high producers
- egg bound
- excessive coelomic fat
- malnutrition / seed diet
- secondary infection following yolk retention
Presentation SBL
- weight loss but possible abdominal distension
- ruffled plumage
- anorexia
- lethargy
- if the birds are still laying eggs they often appear deformed soft shelled etc
Describe how you could confirm a diagnosis of suspected salpingitis / metritis ?
Salpingitis / metritis
Diagnosis
There may be a leukocytosis, either heterophilic or monocytic
- hypercalcaemia (reproductively active bird)
- hyperamylasaemia - high amylase levels / pancreatitis
- radiography may reveal retained eggs or enlarged oviduct
- ultrasound may distinguish fluid, organ enlargement and retained eggs
What are your recommendations to an owner following a case of salpingitis / metritis ?
Salpingitis / metritis
Treatment - Short term
Conservative treatment may be attempted, but is usually unsuccessful
- reproductive rest through environmental cues
- NSAIDS (meloxicam
- need to be clear this is the end of the birds reproductive life
Long term treatment
- Salpingohysterectomy
- although we do not remove the ovary and some birds may continue to ovulate leading to yolk related peritonitis.
Describe the pathology and presentation of yolk related peritonitis ?
Yolk related peritonitis
Yolk related peritonitis is the result of an intense inflammatory reaction to ectopic yolk and ova in the coelom
Pathology
- Ectopic ovulation caused by either
- failure of infundibulum to capture ovulating yolk (fat, trauma, disease)
- or retropulsion of the yolk from oviduct into coelom (metritis association, or cystic hyperplasia)
Presentation
- This condition is usually seen in high producing hens especiatlly cockateils
- usually sterile but if septic presents like septicaemia
- fluid producing inflammatory reaction - dyspnoea, coelomic distension and weakness
- production of malformed eggs (often elongated)
- may develop secondary diseases
Describe how you could diagnose and treat a case of yolk related peritonitis ?
Yolk related peritonitis
Diagnoses
- marked leukocytosis
- hypercalcaemia and lipaemia in breeding bird
- ultrasound; coelomic fluid distension
- coeliocentesis; brown to yellow coloured fluid with mesothelial cells
Treatment
Best salpingohysterectomy and surgery to lavage the coelom
- remove inspissated yolk and adhesions
- short term may manage through meloxicam, antibiotics and hormonal manipulation to stop ovarian activty
Describe the pathology and general presentation of egg binding in birds.
Egg binding (dystocia)
This is a slowed passage of the egg through the oviduct.
Pathology
- within the uterine portion the egg will have a shell, proximal to this it will be incased in a membrane
- it must be distinguished from egg retension.
- loaded egg compresses blood vessels, nerves and cause potential obstruction of the rectum.
Predisposing factors
- old or young birds
- high producers eg cockateils
- malnutrition and obesity / all seed diets
- lack of physical fitness in caged birds
- concurrent disease.
Describe the clinical presentation and diagnosis of egg binding in birds ?
Clinical Presentation
- straining to pass an egg + persistent tail wagging + penguin wide stance
- depression, lethargy
- compression of nerves paresis, paralysis
- compression of blood vessels leads poor organ perfusion and necrosis of the oviduct wall
- dyspnoea, collapse and coelomic distension
Diagnosis
Mostly based off the history of egg laying eg a high producer who suddenly stops lay
- palpation of the coelomic cavity reveals an egg (soft shelled eggs can be difficult to palpate)
Describe you treatment for egg binding in avian species ?
Birds / egg binding TX
If minimal distress
- determine when bird last layed
- calcium gluconate intramuscular injections 3-6hrs
- adequate humidity and temp in a hospital cage
- tube feed highly digestable sugar for a rapid source of energy
Highly distressed animal
- provide oxygen
- PGE2 gel to produce uterovaginal sphincter dilation and muscular contractions
- manual manipulation of the egg into the cloaca and delivery
Take care not to push the egg up against the spine and kidneys.
Desribe the pathology and treatment of an ectopic egg ?
Ectopic egg
Failed passage of egg reguardless of treatment
- This occurs due to rupture of the oviduct at the level of the shell gland
- leaving a fully shelled egg loose in the coelom
Management
- coeliotomy to remove the egg and repair of the oviduct
- good prognosis
- some birds will return to lay eventually
What is a retained egg and how can we treat this pathology in birds ?
Retained eggs
The egg remains in the oviduct, but the bird no longer strains to pass it
- egg may be collapsed (shell only) or intact
Presentation
- often asymptomatic or may have coelomic distension
Diagnoses
- radiographically, eggs may have an extensively thickened shell
- salpingohysterectomy
Describe the pathology and clinical signs observed with chronic egg lay ?
Chronic egg lay
As companion birds (cockatiels) will often excessively lay
- wild birds two to three clutches a year
- captive birds may lay this many in a month
Predisposing factors
- opportunistic breeders which lay their eggs depending on environmental cues
- large amounts readily available food all year round
- high fat sweet foods, fruits
- constant lighting housed indoors
- secure nest site’inapropriate handling
Clinical signs
Left untreated birds deplet their calcium reserves and develop problems such as egg binding or pathological fractures etc
What should we recommend to treat excessive egg lay ?
Treatment for excessive egg laying
(constant drive to lay eggs)
The most important step address environmental cues
- do not remove nest eggs / add fake plastic eggs
- light cycle, social cues and diet
- reduce fat and sugar in the diet
- introduce more foraging behaviour
- if environmental cues are removed may consider hormonal treatment or surgery
Describe the mechanisms of pain and how they relate to avian patients ?
Describe how pain in avian patients will present ?
Pain
Is a response to a noxious stimulus. Avian response to pain is by stimulation of the adrenal gland and subsequent release of corticosterone.
Avian response to pain
Acute pain
- fight / flight
- excessive vocalisation
- wing flapping
Chronic pain
Most birds conservative-withdrawal responses
- immobility
- closure of eyes
- inappetance
- fluffing of feathers
With chronic or overwhelming pain that the bird perhaps feels thay can not escape they may adapt and using masking behaviour to protect themselves.
Localised pain
- may present as self mutilation
This is important as unrecognised pain may go untreated
What is multimodel pain therapy in avian patients ?
Avian; multimodal therapy for pain
- Remove the source of pain
- splint the leg, remove foreign body etc - Reduce fear and stress
- fear and stress may enhance the nocieption pathways
- warm, safe, secure
- judicious use of anxiolytics (midazolam) - Use several classes of drugs to treat pain at different nocieceptors.
Why is it a good idea to use several classes of drugs to treat pain ?
The use of several classes of drugs / synergistic effects
Different drugs act on different nocieceptors
Peripheral nocieceptors detect a painful stimulus and transmit via nociceptive pathways a message to the brain, where central N perceive the pain.
Inflammation in peripheral tissues may sensitise the peripheral N, invoking a more intense pain response at lower levels.
Reccomend an analgesic protocol for use in avian species ?
Avian patient analgesia
Opiod; Tramadol, butorphanol
- act predominantly on kappa receptors
- central acting
NSAID; Meloxicam, Ketoprofan
- COX2 inhibition, act against the effects of prostaglandins in peripheral tissues
A combination of these drugs has a more comprehensive effect as one is centrally acting while the other acts on peripheral nocieceptors.
Describe the unique features of avian anatomy which affects our use of anaesthesia ?
Avian anatomy ; anaesthesia
Trachea
- complete rings, so unable to use cuffed ET tubes
- often long trachea, so a large amount of dead space requiring higher flow rates
- birds have air sacs and lung with no diaphragm
Positioning
- note ventral and lateral are usually the most comforatable for the bird
- yet VD commonly used which places the weight of organs on the air sacs (access)
- if intubating longer than ten minutes use intubation.
Describe how avian metabolism affects anaesthesia ?
Avian metaboloism effects on anaesthesia
(avian metabolism is higher)
Avian patients have a higher risk of hypoglycaemia but also a higher risk of aspiration (air sacs)
Only fast 3-4 hours
- intubate and elevate the head
Avian patients are also more at risk of heat loss
- will begin to cool within 20 mins of induction / loss of voluntary muscle movement
- active warming should be started prior to the pre med
- radiant heating, warmed air (noting feathers can prevent the effects of a heating mat).
What are the Halstead principles ?
Describe the unique character of avian surgical prep ?
Avian surgical prep
Take the time to stabilisze the patient true medical emergenicies rarely occur eg pre treat pain, hydration, pre oxygenation
Surgical prep
- Pluck feathers (do not clip or cut
- minimise feather removal - just enough space to do the job at hand
- chlorhex or iodine (alcohol will cool the patient through evaporation).
- utilise transparent drapes / lone star retractor for draping and towel clamp around feathers not through the skin
- maintain temperature Bair hugger
feathers are insulating the bair hugger will ruffle feathers - if fluid loss anticipated (orthopedics) IV patient
Identify this piece of surgical equipment ?
Lone star retractor drape
Describe the unique features of avian skin and its closure in surgery ?
Unique feature of avian skin as they relate to surgery
Avian skin is only 1mm thick in some areas
- skin is closely attached and very thin used as holding layer in avian patients
- the subcutaneous layer is extremely fatty so will not hold sutures
- additionally post op swelling tends to be reduced in avian patients
-CAN’T GET PRIMARY CLOSURE, HEALING IS BY SECONDARY INTENTION
This means for avian surgery holding sutures are placed as tightly as possible through the skin.
(birds usually do not pick at skin sutures).
What unique features do birds have that enable them to withstand a comparitively greater blood loss when compared with mammals ?
Avian blood loss
Birds have a greater ability to with stand blood loss compare to mammals
(fluid support, warmth and blood transfusion can still be utilised)
- Increased capillary surface area
- can restore blood volume through extravascular fluid resorption - Ability to mobilise large numbers of immature erythrocytes
- Extrinsic pathway
- lack autoimmune response to haemorrhage that leads to haemorrhagic shock
Describe the unique features of hetrophils in avian species ?
Heterophils
Heterophils lack lysozymes
- unable to liquify pus, so avian pus is caseated
- drains do not work well in surgery (flushing is also not particularly effective)
If you come across infected wounds - best to debride and leave to heal by secondary intention.
Describe the procedure vof an Ingluviotomy ?
Ingluviotomy / crop repair
Approach via apterylae
(avascular area, skin then crop)
- blunt disect to seperate and treat as two layers
- remove foreign body
- closure two layers of inverting sutures in crop then close to skin
Describe the process of a coeliotomy in avian species ?
Coeliomtomy
Left flank or ventral midline appraoch
- proventriculotomy, salpingohysterectomy, liver and kidney biopsy
- intercostal muscles may bleed profusely, ligate where possible
Describe the unique features of orthopedics in avian spcecies ?
Avian orthopedics
(Illegal to amputate in wild species, amputation through bone preferred)
Bones - light weight, this and brittle cortices, poor holding power for screws
- do not consider in birds <1kg
- often open and comminuted
- blood supply - periosteal in humerus, endosteal in others
- fracture callous may imping on ROM <1.5 bone widths from joint
- bone healing is primary
Rtae of healing determined by displacement of fragments, damage to blood supply, pressence of infection and movement at fracture site.
Well aligned fractures will heal faster in birds when compared to mammals
Describe the various types of fracture repair in avian orthopedics ?
Avian orthopedics
External
conservative repositioning using bandages
- often better outcomes as it reduces complication rate
- Figure of eight bandage, quality temporary support (first loop outer three primary feathers)
- Tape splint
Post operative antibiotics, banadage support and early return to function
eg physiotherapy start at 1-2 days
Distinguish the important anatomical differences between rats and mice ?
Anatomical differences mice vrs rats
Rtas and mice
- obligate nasal breathers
- omnivores
- open rooted dentition with yellow tinge in the incisors dur to the incorportaion of iron into the enamel.
Rats (4-5 years)
- continuous feeders, no gall bladder as no need to store bile
- mammary tissue 6 sets in rats
Mice (2 years)
- have a gall bladder
What are the benefits of sterilisation in rats.
Mostly rats sterilised around 12 months of age
Benefits
- reduced fighting if owner has multiple animals
- preventing unwanted pregnancy
- eliminates the risk of testicular cancer
- reduces the risk of many pituitary and mammary cancers
- reduces male odour
- red
Often enables a better bond to develop between the owner and their pet.
Sexing mice rats is via the ano-genital distance
- twice as long in the male vrs the female
Describe the presentation of illness in mice and rats ?
Signs of illness in mice and rats
- increased porphyrin staining
porphyrin containing secretions aid ocular lubrication and may play a role in pheromone mediated behaviour (red tinge)
In health spread over the fur during daily grooming - increased snuffling sounds in the nose and upper respiratory tract
- sneezing and mucous from the nose
- breathing faster and harder
- lumps / bumps
- hair loss
- weight loss lethargy
- hunched back
If dyspnea is suspected minimise handling, as the patient may die
What are the two main causes of respiratory disease in mice and rats ?
Rats and mice respiratory disease
The most common pathogens involve
Mycoplasma
Streptococcus pneumoniae
Describe the pathogenesis and diagnosis of mycoplasma ?
Mycoplasma
(upper respiratory signs)
Pathology (underlying stress disease, or disease allows mycoplasma proliferation.)
- multifactorial; environmental, bacterial +/- viral
- transferred by aerosolisation or female rat to her babies
- normal habitant of the respiratory tract / opportunistic
Diagnosis is difficult
- collection of tracheal or nasal secretions is not reccomended swabbing can be highly traumatic.
Describe the pathology underly a streptococcus. pneumonia infection in rats ?
Respiratory disease, Streptococcus pneumoniae
Pathology
- young rats more severely affected then older ones
- may exhibit sudden death
Mature rats
- dyspnea, snuffling, abdominal breathing and a purulent exudate can be seen around the nares and paws (from wiping nostrils
Diagnosis
- tentative numerous gram +ve diplococci on a gram stain of exudate
Treatment
Amoxicillin / clauvulanic acid or penicillin
Describe the main environmental factors which contribute to respirtory disease in rats ?
Ammonia
The environment plays a major factor as ammonia building up in the environment can strip cilia from the respiratory tract
Ammonia can destroy cilia, which then allows bacteria to enter the respiratory tract
Solution
- frequent thorough cleaning of rat cages
- well ventilated cages with wires
How do you adress respiratory disease in rats ?
Address respiratory disease in rats
Treatment of respiratory disease is ofetn aimed at control rather then a cure.
- unfortunately in rats once respiratory disease occurs, it usually is present for life
- although resp signs may clear up with the right treatment they will likely recur
Treatment
- doxycycline
- amoxycillin and clauvulanic acid
Write a differential list of common skin disorders in mice and rats and how they present ?
Common skin disorders mice and rats
Barbering
- dominant mouse, usually female nibbles off the whiskers and hair around the muzzle of cage mates.
Fighting
- usually male to male are more likely to fight and cause bite wounds
- especially over the rump, tail and shoulders
- reccomendation is to isolate the aggressor ontop of treating wounds in cage mates
Mites / Lice are common
- in affected animals the hair is generally thin especially in difficult to groom areas such as the head and trunk
- greesy appearance to coat
- puritis and self inflicted dermal ulceration may occur
- Treatment ivermectin
Describe the different presentations of neoplasia in mice and rats ?
Neoplasia mice and rats
extemely common inbred strains >70% in some lines
Pet mice most commonly
- mammary tumours adenocarcinoma and fibrosarcoma
- primary lung tumours
- most are malignant and metastatic, often ulcerated by the time a diagnosis is made
Rats primarily present with
- fibroadenoma of the mammary glands
- surgery is viable depending on size of the tumour, good prognosis
- recurrence of fibroadenomas are common in rats with repeat surgeries often required
- usually dont metastasize but may kill the rat due to space occupation.
Describe the importance of speying in guinea pigs ?
Guinea pigs
(very advanced off spring - desex can start breding 4-8 weeks of age
(Desexing 5-6months F, and 3-4 months male)
Must be bred or desexed prior to six months to avoid future dystocia.
- a female guinea pig must have her first litter prior to six months of age
- F at six months the pelvic bones become fused and can cause problems during labour
- desexing reduces the risk of ovarian cyst
- reduced risk of faecal impaction males
In almost all cases sterilised guinea pigs will bond better with their owners and other guinea pigs
Describe how a guinea pig will present when ill ?
A sick guinea pig will often present with;
- weight loss
- reduced eating
- eating only soft foods, no longer eating hay
- drooling
- diarrhea
- lethargic
- not grooming unkept coat
- lumps and bumps anywhere on the body
- sores on their feet
A large % arepresented moribund collapsed, and severely hypothermic <35 End satge = poor prognosis
You are presented with a seizuring guinea pig when touched - what is your number one suspect ?
Parasites mites
Often presented seizuring - the puritic response is so intense
Presentation
- hair loss
- flaking
- self excoriation of back, thighs, shoulders and neck
Treatment -
- ivermectin 2-3 treatments 10 days apart
Describe the pathology and presentation of vitamin C deficiency in guinea pigs ?
Vitamin C deficiency Guinea pigs
(unable to produce vit C, must obtain from fresh vege in the diet)
Some animals are more susceptable
- growing, pregnant, elderly or sick guinea pigs
- a complete vit C deficiency results in a more rapidaly progressing form of disease
Presentation
- flaky rough coat / not puritic
- painful swollen joints
- lameness
- teeth grinding vocalisation from pain
- bloody urine or diarrhoea
- stasis death
Treatment
- vitamin C via injection or oral medication
- oxbow vitamin C supplement in water but note the vitamin is unstable in light
- good quality guinea pig pellet food
- fresh fruits and vege eg kale
Vitamin C can be destroyed easily by light / heat - so the fed must be stored in a cool dark place.
Identify this pathology and its cause ?
Pododermatitis
Pathology
- The development of pressure sores on the feet of guinea pigs
- most common on the heels and hind feet
- early signs redness and inflammation of the exposed skin in guinea pigs
- as the condition worsens may lead to lameness, swelling and ulcers
Contributing factors (usualy a combination of factors)
- hard floor surface such as carpet, wire
- dirty damp bedding
- poor diet, obesity and inactivity
- deformity of the leg
- small cages and lots of turning
- trauma eg already existing inflammation
Describe what we can do to treat pododermatitis ?
Tx pododermatitis in guinea pigs
This is a difficult condition to treat successfully
This is because even bearing weight on the affected limb will slow its healing
- address underlying cause eg bedding, flooring, rads
- sores must be treated debridementto remove any dead tissue
- appropriate dressings and bandages
- potential need for antibiotics
“bootees if there are ulcers or open wounds
Identify this pathology
Faecal impaction
(entire males >2-3 years of age)
Pathology
- increased size of testicle and fat becomes deposited in the scrotal sac
- this prevents faeces from leaving the rectum
- the area dilates to accomodate more faeces
- still able to pass normal faeces but usually show symptoms of straining to defaecate or unusual odour
Prevention / treatment
- prevented by early castration
- treat cleaning 1-10 times a week depending on boar.
Describe the common causes and presentation and tx of vestibular disease ?
Vestibular disease
Presentation
- head tilts, rollings and “seizures” nystagmus
Causes
- bacterial infection, ear infections and protozoan infections
- trauma
TX
- ear examination and radiograph
Describe the pathology and presentation underlying dental disease in guinea pigs ?
Dental disease guinea pigs
Pathology
- lack of fibre eg pellets or piggy mixes
- open rooted teeth which continuously grow
- the lower cheek teeth in GP are curved inwards
- when not ground down appropriately they will grow towards each other and eventually entrap the toungue
- interfers with GP ability to chew and swallow
Presentation
- stops eating hard foods or any food at all
- weight loss
- fewer smaller droppings
- excessive saliva (drooling)
- leading to fur matting under the jaw
Describe how you could diagnose and tx a case of maloclusion ?
Guinea pig maloclussion
(low fibre growth of lower cheek teeth)
Diagnosis
- oral exam, nasal speculum
- potential rads to confirm degree of overgrowth
Treatment
- surgery to grind down teeth
- requires special dental jigs to open the mouth as oral cavity very small
- grind teeth back with dremel / dental burs
- prevention a diet including atleast 70% grass/ quality hay oat, timothy + 20% fruit/vege
- guinea pigs also require daily supplementation with 25-50mg of vitamin C tablets
May need to be carried out as freqently as every six weeks if chronic changes
Describe the pathology and presentation of ovarian cyst ?
Ovarian cyst
Most commonly occur in entire females 2-5 years of age
- cystic changes present on ovaries
- functional ovarian cyst secrete hormones which may cause bilateral symetrical hair loss in the flank region
- crusty nipples
- also may cause irrtability or discomfort in the abdomen
- may be associated with uterine disease
Ovarian cyst if left untreated can become significant space ocupying masses
- causing anorexia, depression or lethargy
- increase in size with time and may also form adhesions.
Describe how you would diagnose and tx an ovarian cyst in guinea pigs ?
Ovarian cyst guinea pigs
Diagnoses
- is usually by abdominal palpation but may be confirmed via ultrasound
Treatment
- short term ultra sound guided aspiration under sedation = temporary solution with risks
- Exploratory laporatomy to remove cyst and ovariohysterectomy (best option)
Decribe ecdysis in lizards and snakes ?
Ecdysis - skin shedding / sloughing
Physiology
- snakes tend to shed the entire skin in one piece from snout to vent
- lizards occurs piece meal
- the shed is colourless because the pigment cells remain in the dermal layer
Physiology
- Shed is controlled by the thyroid gland
- the cells in the intermediate layer replicate to form a new layer epidermis
- lymph diffuses into the area between the two layers and enzymes are released at the cleavage zone
- old skin shed
- new skin hardens to form new skin
Snakes takes around two weeks may become sluggish and go off food.
Describe dyssecdysis and its pathology ?
Dyssecdysis - failure to shed
This usually occurs due to environmental humidity or when the reptile is ill.
- malnutrition and debiliatation leads to dehydration and hypoproteinaemia, rendering them unable to produce enzymes for the production of the cleavage zone
Describe the common techniques for sex determination in reptiles ?
Sex determination techniques in reptiles
Techniques vary between groups and between species and within those groups
- many species have limited external features eg snakes
Probing snakes
- most reliable and safe in most species
- determine the depth of hemipenal pockets with a blunt probe (longer in males)
- clean crop needle, probing needles may be purchased
(except green tree pythons)
Snakes
- males may present with large cloacal spurs
Lizards
- probing may cause damage
- Popping forcing hemipenal exposure with digital pressure
- visual differences between the sexes (sexual dimorphism)
- Radiographs - monitor calcified hemibacula
- hemipenal translumination
Turtles
- tail length
- notch
- plastron shape
Describe the pathology and presentation of metabolic bone disease ?
Metabolic bone disease
A complex intercation between the uptake and utilization of calcium and vitamin D3 with adequate and appropriate exposure to UV light.
The initiating factors can take place well before new owners take possession.
bent malformed bones.
Describe the pathology behind early onset, late onset and delayed onset MBD ?
Metabolic bone disease
Early onset
- associated directly with a lack of UV / and or calcium in new hatchlings
- may develop 7 days post htach
Late onset MBD
- one month onwards
- appear to initiate growth normally, but as growth accelerates problems arise
- structural components of the body collapse under increased weigt gain associated with growth
- may also have seizures, weakness andoccasional spinal fractures
Delayed onset
- Often well past 12 months of age
- spontaneous fractures to the spine or limbs
- sudden paralysis
- weakened skeleton
Describe the pathology underlying fatty liver / obesity in reptiles ?
Reptile; fatty liver obesity
Fear of underfeeding causes the opposite effect
Pathology - constant feeding
- there is also frequently a push for power feeding
- forced growth rates result in misshapen, overweight individuals with shortened lifesapns
- pin head snakes
Fatty liver is often observed in lizards
- simple result of constant feeding
- prevention of brumation through out winter is a common scenario
-deaths are usually brought about by haemorrhage from fragile friable liver
- to treat do not starve risk of lipaemia, fluid therapy essential
Treatment may take months to years to achieve a resolution and weight loss
