Problems with pregnancy in the mare Flashcards
1
Q
Up to what day is a conceptus termed an embryo?
A
40 days of gestation
2
Q
What are the 8 causes of embryonic loss in mares?
A
Endocrine Oviductal environment Genetic abnormalities Uterine environment Maternal age Insemination over 6 hours post ovulation Site of intrauterine fixation Malnutrition
3
Q
What are some ultrasound signs of early embryonic loss?
A
Irregular shape of vesicle Prolonged mobility of vesicle over day 16 Excessive endometrial oedema Fluid within uterine lumen Undersized embryo for age Loss of heartbeat Decrease in fluid surrounding embryo Increased echogenicity of fluid within the conceptus
4
Q
If by what day after conception should you terminate a pregnancy if there is no heart beat?
A
Day 30
- Use PGF2alpha
- Before endometrial cups form
5
Q
What days should you do serial examinations after conception to detect a problem with the embryo?
A
Days 12-60
6
Q
What is uterine body pregnancy?
A
Embryo becomes fixed in the uterine body rather than at the base of a uterine horn
7
Q
Why does pregnancy loss occur in uterine body pregnancy?
A
Placental insufficiency, retarded foetal growth
Abortion late in gestation
Rare
8
Q
What is hydrops?
A
Excessive accumulation of foetal fluids within the foetal membranes
9
Q
What is hydrops amnion?
A
Foetal problem, increased fluid amnion
10
Q
What is hydrops allantois?
A
Placental problem, increased fluid allantois
Is more common
Over 7 months gestation
11
Q
What are clinical signs of hydrops?
A
Enlarged abdomen Rectal palpation feel enlarged uterus, foetus may not be palpable Depression Anorexia Abdominal pain Ventral oedema Reluctance to move and difficulty moving Tachypnoea and dyspnoea
12
Q
How do you treat hydrops?
A
Induce abortion as foetus usually non-viable
Pre-treat mare with IV fluids and gradual siphoning of fluid via transcervical catheter
Assist birth to avoid dystocia
Supportive treatment to manage any complications associated with retained placenta, metritis, laminitis
Is unlikely to recur in the future
13
Q
What is the cause and predisposing factors of ventral abdominal ruptures?
A
Rupture of prepubic tendon, rectus abdominus muscle or hernia
Factors - Older mares, twins, hydrops allantois, draught breeds, trauma
14
Q
What are clinical signs of ventral abdominal rupture?
A
Ventral swelling Oedema Abdominal pain Recumbency Swelling of udder Saw horse stance Subcutaneous haemorrhage Cold abdominal skin
15
Q
How do you treat a mare with a ventral abdominal rupture?
A
Poor prognosis
Either aim to save the mare or the foal
Save mare by inducing parturition
Save foal by applying support wraps and nursing until parturition can be induced
If medical management cannot be undertaken then euthanasia
16
Q
What is luteal insufficiency?
A
When luteolysis or inadequate concentrations of P4 occur up to days 80-120
Result in pregnancy loss
17
Q
How do you treat luteal insufficiency?
A
Altrenogest orally daily
Daily injections of progesterone in oil
Microencapsulated formulations every 7 days - USA
-Treat until the placenta can produce enough progesterone by itself - Day 150 to be safe
18
Q
In a pregnant mare what is the minimum progesterone concentration?
A
4.0 ng/mL
19
Q
What should you do if you detect a twin pregnancy?
A
Crush/pinch one
Terminate pregnancy and recycle mare
If unilateral may leave and monitor, hopefully will naturally get rid of one
20
Q
What can you give prophylactically to manual twin reduction?
A
Lignocaine to relax tone of rectum
-Afterwards can give NSAIDs and progesterone
21
Q
What is the normal gestation length for a mare?
A
340 days
22
Q
Under what gestation length is it considered to be an abortion?
A
Under 300 days
23
Q
What do you need to examine after an abortion of the foetus and placenta?
A
Placenta and umbilical cord
Weigh them
Assess foetal size, crown-rump length, autolysis
Small foetus suggests growth retardation from chronic placental disease
Foetus of normal size suggests acute abortion
24
Q
If an abortion was caused by an anscending infection, what will you see on the placenta?
A
Thickened area extending from the cervical star
25
What is a 'red-bag' and what causes it?
Dramatic colour difference of tissues (chorioallantois) that were prematurely separated
-Premature placental separation
26
What samples should you collect from an aborted dam?
Uterine swab
| Serum samples -One right now, another in 2-3 weeks
27
What are some management strategies if an abortion was potentially caused by an infectious agent?
Isolate aborting mare/s
Isolate and monitor in-contact mares
Separate in-contact mares into smaller groups
Quarantine affected pasture
Do you need EHV-1 vaccine?
Control and quarantine any introduced horses and advise restricting departures from property
28
Is EHV-1 contagious and/or notifiable?
Yes to both
- Highly contagious
- Notifiable
29
What does EHV-1 cause?
Respiratory disease
Neurological disease
Abortion
Neonatal deaths
30
How is EHV-1 transmitted?
Ingestion or inhalation
31
How long does EHV-1 survive in the environment?
14-42 days
32
What is the incubation period for EHV-1?
Highly variable
| Abortions can occur 1-4 months after infection
33
When does abortion occur from EHV-1?
Mid-term to late gestation
5 months+
-But rare for a mare to abort again from EHV-1
34
What is the role of latency with EHV-1 infection?
Latently infected horses can become reactivated and nasal shed
Then infect young horses and pregnant mares
35
What are clinical signs of an EHV-1 infection?
```
No maternal illness usually
Foetus
-Fresh or autolysed
-Placenta may be attached
- +/- pulmonary oedema, hydrothorax
```
36
How do you diagnose an EHV-1 infection?
Fluorescent antibody test
Virus isolation
PCR
Histopathology for intranuclear inclusions
37
What is the vaccination protocol for EHV-1?
Pregnant mares at 5, 7, 9 months
38
How do you manage and control an outbreak of EHV-1?
Place aborting mare/s in isolation - leave in paddock where aborted and move other horses
Dispose foetus and membranes and clean contaminated area
Suspect EHV-1 until proven otherwise
Prevent the spread
In contact pregnant mares should be isolated until 30 days post-foaling
If positive for EHV-1 split in-contact mares into smaller groups
The environment is 'clean' again after 21 days with no horses on it
39
What is the situation with Equine viral arteritis in Australia?
Notifiable disease
Present in Australia but low virulence strains
Disease associated with infection not yet recorded here
40
What are clinical signs of Equine viral arteritis?
```
Generalised or subclinical maternal respiratory disease
Vasculitis
Generalised oedema
Haemorrhage
Abortion at 5-10 months
```
41
What is the most common cause of abortion in mares?
Bacterial placentitis?
42
What are the 2 routes of infection for bacterial causes of abortion?
Transcervical - ascending
| Haematogenous
43
What is the most common bacterial cause of abortion in mares?
Streptococcus zooepidemicus
| Less than 200 days gestation
44
What is the second most common bacterial cause of abortion in mares?
Escherichia coli
| Over 200 days gestation
45
What are signs that nocardioform placentitis has caused an abortion?
In 3rd trimester
Or if early, will be small and weak usually
Usually sporadic
Restricted to placentitis
-Affected chorion has thick, brown exudate
Foetal tissues not infected
46
What causes equine amnionitis and fetal loss syndrome?
Ocrogaster lunifer
| -Caterpillar
47
What are the clinical signs of equine amnionitis and fetal loss syndrome?
Abortion under 70 days, or over 9 months
Coincides with abundance of caterpillars
Mares may get pericarditis and uveitis
Aborted foals have bronchopneumonia and funisitis
48
What is the pathogensis of the Ocrogaster lunifer caterpillar?
Ingested
Barbed setal fragments breach GI mucosa
Rapid haematogenous spread of bacteria
49
Do fungi usually cause abortion storms, or individual cases?
Sporadic individual cases
50
What is the most common fungal cause of abortion in mares?
Aspergillus fumigatus
51
How do fungi that cause abortion infect mares usually?
Ascending infection
52
How do fungal causes of abortion cause pathology?
Get progressive placental insufficiency
Intrauterine growth retardation
Abortion of dead or non-viable foetus
53
What will you see on pathology in a placenta from an aborted foetus of fungal origin?
Placenta diffusely involved
Thickened
Leathery
Clear demarcation from normal, reddish chorioallantois
54
How do you diagnose that a fungi caused an abortion in a mare?
Sample the chorioallantois
- Smears with fungal hyphae
- Histopathology
- Culture
55
What 4 things can you do to prevent bacterial and fungal causes of abortion in mares?
Want to prevent ascending infection
- Sanitary breeding and examination practices
- Surgical correction of abnormal conformation
- Control endometritis
- Prophylactic antibiotics
56
What are some clinical signs of placentitis or late pregnancy failure?
Vulvar discharge
Premature lactation
Placental thickening
Increased cellularity of allantoic and amniotic fluid
Foetal tachycardia
Fluid accumulation between chorion and uterus
Foal low birth weight
Premature increase in milk Ca concentrations
Decreased Sodium and increased potassium
57
What appearance will the amniotic fluid have in a mare with placentitis or late pregnancy failure?
Hyperechoic
58
What are the 2 main causes of placentitis or late pregnancy failure?
Bacterial placentitis
| Twins
59
What is the CTUP and why is it important?
The Combined Thickness of Uterus and Placenta
- Help to assess pregnancy viability throughout gestation
- Measured via ultrasound
60
What value should the CTUP never go above?
1. 5cm
| - Take multiple measurement
61
What value of progesterone indicates an abortion is likely?
Over 2ng/mL over 3 consecutive days
62
What changes in mammary secretions occur in the last days of pregnancy?
Over last 6 days calcium progressively increases
| 3-5 days prior Potassium increases while Sodium decreases (Inverted to normal values)
63
After birth when should the placenta be expelled?
Within 3 hours
64
What are 3 good indicators after parturition on a rectal exam of the uterus?
Presence of rugae
Good uterine tone
Good contraction
65
What is a 'red bag'?
Premature placental separation
The chorion separates from the endometrium but does not rupture
May be seen bulging through vulval lips
66
What can occur as a result of a 'red bag'?
Foetal hypoxia
67
How should you treat premature placental separation?
Make sure that it isn't a bladder prolapse
Rupture chorioallantois manually
Deliver foetus ASAP
+/- supplemental oxygen for foal
68
What is the most common cause of death in postpartum mares?
Uterine artery rupture
69
How do you diagnose a uterine artery rupture?
```
Clinical signs are non-specific
-Lethargy
-Anxiety
-Colic
-Tachycardia
-Cardiovascular shock
On rectal exam
-Swelling of broad ligament
On Ultrasound, abdominoparacentesis, vaginoscopy
-Detect blood in peritoneal cavity
```
70
What is a good prognostic indicator in a uterine artery rupture?
That it is confined in the broad ligament
| If haemorrhage escapes this, death from hypovolaemia likely
71
What 5 things do you aim to do in treating a uterine artery rupture?
Control pain and anxiety
Promote haemostasis
Treat hypovolaemia and hypotension
Antibiotics for secondary bacterial infection
Confine to stall with minimal disturbance
72
What are clinical signs of a uterine torsion?
```
7 months to term
Colic
Restless
Sweating
Anorexia
Frequent urination
Sawhorse stance
Looking at flank
Kicking abdomen
Vital signs normal or slightly elevated
```
73
How do you diagnose a uterine torsion?
Rectal exam feel for tense broad ligaments
| Cervix is often not involved so vaginal exam not helpful
74
What are the 3 methods to fix a uterine torsion?
Manual detorsion via cervix
-Only if under 270 degree rotation
Rolling
-Uterine rupture likely if near full term
-GA, place into recumbency, roll with plank keeping uterus still
Surgery
-If nothing else has worked
-Flank laparotomy or ventral midline
-Especially if uterus may have been compromised
75
What are clinical signs of a uterine rupture?
Excessive blood and clots on vaginal exam
Intestine detected on vaginal examination
Colic
Depression, fever, anorexia as peritonitis develops
Abdominoparacentesis has elevated TP, WBC count, neutrophils
If haemorrhage extensive will have signs of blood loss
76
How do you treat a uterine rupture post-partum?
Systemic broad-spectrum antibiotics
NSAID to prevent developing endotoxaemia
Oxytocin every 2 hours to promote involution
Small dorsal tear may be managed by medical management +/- blind suturing
Large, full thickness tears repair surgically via laparotomy
77
What type of prolapse can occur in the post partum mare?
Uterine
| -Vaginal prolapses don't occur in horses
78
How do you treat a uterine prolapse?
```
Wrap tail
Wash uterus
Suture deep lacerations
Elevated hind end of mare and keep standing
Replace back into vagina
Control straining if needed
Distend uterus with saline to make sure tips of both horns are extended
Siphon fluid
Repeat oxytocin every 2 hours
Broad spectrum antibiotics
NSAID's
Tetanus prophylaxin
+/- IV fluids with calcium gluconate
+/- Caslicks
Monitor for complications
```
79
How can you control straining in a mare?
Epidural
Sedation
Nasogastric tube into trachea
General anaesthesia
80
What are some complications that can occur from a uterine prolapse?
```
Haemorrhage
Endometritis/metritis
Ischaemic damage to bowel
Septicaemia
Endotoxaemia
Laminitis
```
81
When is a retained placenta more likely?
Dystocia
Placentitis
Abortion
After c-section
82
What are some complications that can occur from retained placenta?
```
Metritis
Toxaemia
Laminitis
Death
Infertility
Delayed uterine involution
Reduced fertility
```
83
Describe oxytocin therapy for treatment of a retained placenta?
30-60 IU instilled in 1-2 litres of saline IV over 30-60 minutes
OR
5-20 IU IM every 3 hours
*NSAID and systemic antibiotics
-After 24hours oxytocin has a reduced effect
-If after oxytocin therapy and 18-24 hours have passed, give 23% calcium gluconate in saline followed by IM oxytocin
84
What should every mare with a retained placenta receive?
NSAID's
| Systemic antibiotics
85
In a mare with a retained placenta which oxytocin has failed to work, what are 3 treatments that can be used?
No touch technique
-Treat systemically and don't invade uterus
Burns technique
-Fill with water which stimulates endogenous oxytocin and uterine contractions
Manual removal
-Not recommended
86
What are some clinical signs of necrotic vaginitis?
```
May take 3-5 days to see signs
Depression
Reluctance to defecate or urinate
Foul odour from vagina
Strain to urinate
Inappatent
```
87
How do you treat necrotic vaginitis?
```
Do not scrape! ( Increases inflammation and uptake of toxins)
Systemic antibiotics
Tetanus toxoid
+/- metronidazole
Faecal softeners
NSAID
+/- catheterisation if urethra lacerated
```
88
What are some reasons for a perineal laceration occuring?
```
Malpositioned foetus during delivery
Heavily muscled mare - QH
Maiden mares
Failure to open Caslick's before foaling
Panic during delivery
Less relaxed canal and prominent vestibulo-vaginal fold
```
89
What are the classifications of perineal lacerations?
1st degree
-Only vulvar lips
2nd degree
-Vulvar lips and perineal body, rectum intact
3rd degree
-Extends through rectovaginal shelf, perineal body, anal spincter, vulvar lips
90
How should you immediately treat a perineal laceration?
```
Topical cleansing
Tetanus toxoid
NSAID
Antibiotics
-Delay surgical repair until all oedema and inflammation subsided, 4 weeks
```
91
What is a rectovaginal fistula?
Communication between the rectum and vagina
| But the perineal body, anal sphincter and vulvar lips remain intact
92
How should you treat a rectovaginal fistula?
```
Clean
Antibiotics
NSAID
Tetanus prophylaxis
May leave for 5 weeks to see if it will heal by secondary intention
If not, then correct surgically
```
93
Why is trying to fix a cervical laceration or adhesion important?
Otherwise they will have poor future fertility
Either will develop endometritis and won't conceive
or lose the pregnancy in 1st or 3rd trimester
-Even with treatment there is a poor prognosis
94
How should you treat a cervical laceration or adhesion?
Topical application of antibiotic/steroid cream on edges to prevent adhesions forming
Systemic antibiotics
NSAID
Tetanus prophylaxis
Wait for some healing to occur
-Surgical repair
Evaluate need for surgery during dioestrus (If cervical seal is competent or not)
If incompetent then surgical reconstruction and removal of adhesions
95
What are some GI complications that can occur as a result of parturition?
```
Bowl rupture
Trauma
Contusions
Mesenteric rupture leading to incarceration or occlusion
Rectal prolapse from straining
```
96
What can happen to the bladder during parturition?
Rupture
Become bruised
Prolapse
97
What are some signs of a GI and urinary complication during parturition?
```
Depression
Colic
Anorexia
Anurea
-Especially within 24hours of foaling
```
98
What is post partum eclapmsia also known as?
Lactation tetany
| Hypocalcaemia
99
What is post partum eclampsia generally associated with?
Some sort of stress
- Weather
- Transportation
- Change in surroundings
- etc.
100
What are some clinical signs of post partum eclampsia?
```
Restless
Excitability
Tachypnoea
Staring eyes
Muscle fasiculations
Trembling
Clonic spasms
Later clonic spasms become tonic and eventually mare cannot stand
```
101
What is the differential diagnosis for post partum eclampsia?
Tetanus
| But nicitating membrane not prolapsed
102
How do you treat a mare with post partum eclampsia?
IV Calcium gluconate slowly
| Monitory cardiac signs
103
What are some indications for inducing abortion?
```
Mismating
Abnormal pregnancy
-Hydrops allantois
Twin pregnancy
Rupture of prepubic tendon
Rupture of abdominal musculature
```
104
How can you induce abortion between days 0-33 of gestation?
PGF2alpha and its analogues
In days 12-33 may need to injections
Also you can-
*Intrauterine infusion of antiseptic before day 6
*Manual crushing of conceptus
*Transvaginal ultrasound guided reduction
*Ovariectomy
105
If you induce abortion between days 34-120, what do you need to warn the owner?
That the endometrial cups are active and mares may not return to oestrus for some time after termination
106
How can you induce abortion between days 34-120 of gestation?
PGF2alpha and its analogues given 1-2 daily until abortion occurs
Intrauterine infusion/lavage after manual rupture of attachment of chorioallantois +/- extraction of foetus (Before 80 days)
Manual crushing (Difficult per rectum after 34 days)
Transvaginal ultrasound guided injection of foetotoxic chemical
107
How can you induce abortion after day 120 in a mare?
-Mare needs to be monitored closely for complications
PGF2alpha and its anaolgues multiple injections - x2 daily until abortion
Manual disruption of foetal membranes and removal of foetus
-Soften cervix with oestradiol 24hours prior
Transabdominal ultrasound guided foetal injection of KCl or procaine penicillin
108
What should you not give to a mare to induce abortion?
Systemic corticosteroids
- Ineffective
- Can develop laminitis
109
What are some indications for inducing parturition?
Desire to supervise foaling during daylight hours
Pathological pregnancy
Medical indication that foetus is deteriorating
Dead foetus
-But unless indicated, better to leave alone since higher chance of complications
110
What is the normal gestation length in the mare?
310 - 380 days
111
What factors can lengthen gestation length?
Mares that conceive early in breeding season
Male foetus
Ingested toxins
Severe foetal abnormalities
112
What 7 things should you check/examine before inducing parturition?
Mating and due dates
Previous history
Examine mare - If she is pregnant, foetus alive, orientation
Vaginal exam to assess cervix
Udder to determine if colostrum
Milk concentration of CaCO3 (Over 200 ppm)
Na:K ration
113
Describe a method for inducing parturition in the mare?
- Instil PGE2 into external os of cervix 4-6 hours before to promote cervical softening
- Place IV catheter
- 10-20 IU oxytocin IV OR slowly infuse 50 IU in 1L of saline
- Monitor time
- Evaluate in 15-20 minutes
- Check to see if the chorioallantois has rupture and if the foal is presenting normally
- If normal then give 2nd dose IV oxytocin, or continue IV infusion
114
What do you need to remember about mare monitoring systems like Foal Alert?
That if the foetus is malpresented and doesn't enter birth canal or part vulval lips, then the device won't be activated
