Equine Abortions Flashcards
1
Q
abortion in mares
A
- expulsion of the non-viable fetus and its membranes between 50 and 300 days of gestation
2
Q
main causes of equine abortions
A
- twin pregnancies
- umbilical cord torsion (UK)
- viral, bacterial or fungal infections
- digestion of a large amount of eastern tent caterpillars
3
Q
twin pregnancies in mares
A
- insufficient placenta for twins
- usually late abortions
4
Q
umbilical cord torsion
A
- etiology
- excessively long umbilical cord
- more than 5 twists
- blood flow restriction
- fetal death and/or abortion
5
Q
viral abortions
A
-
Equine rhinopneumonitis“Rhino”
- Equine Herpesvirus 1
- reportable disease
-
Equine Viral Arteritis
- reportable disease
6
Q
Equine Herpesvirus 1
A
- repiratory disease, neurological disease, abortion
- transmission
- respiratory, contact with infected tissue, fetuses, placenta, fluids
- virus viable for several weeks in the environment
- endemic to USA
7
Q
clinical signs of EHV 1
A
- no clinical signs until abortion
- late abortions: 7+ months of gestation
- abortion of fresh fetus
- possible “abortion storms” in not vaccinated horses
8
Q
diagnosis of equine abortions caused by EHV 1
A
- aborted fetus and fetal membranes
- necropsy: necrotic foci of the liver and edematous lungs
- histopathology: eosinophilic inclusion bodies
- virus isolation
- PCR
9
Q
treatent and prevention of EHV 1
A
- no specific tx
-
supportive tx, if needed
- most ifnected foals die shortly after birth
- prevention
- separating pregnant mares from younger animals
- vaccinations during months 5, 7, and 9 of pregnancy (3 vax)
10
Q
Equine Viral Arteritis
A
- contagious viral disease of equids which can cause abortions in mares and carrier status in stallions
- global distribution
- causative agent: equine arteritis virus (EAV), genus Arteriviridae, order Nidovirales
11
Q
transmission or EVA
A
- respiratory or venereal
- stallions: carriers
- virus survives in frozen semen
12
Q
clinical signs of EVA
A
- classic:
- fever
- lacrimation
- nasal discharge
- edema of legs, ventral abdomen, and/or scrotum
13
Q
reproductive consequences of EVA infection
A
- not-pregnant mares bred by infected stallions do not lose pregnancy
- late pregnant mares infected by infected animals (respiratory route) often abort
- abortion storms occur in susceptible mares- up to 50-60%
- aborted fetus is partially autolyzed
- foals infected in utero may develop pneumonia
14
Q
dx of EVA
A
- serum neutralization test
- virus isolation from semen, placenta, fetal tissue, blood
- PCR
- test breed stallions
- if vaccinated, blood can test positive
15
Q
prevention of EVA
A
- test all breeding stallions once a year
-
approved vax
- determine and document serological status of the animal before vax
- inform state vet before using vax
- keep detailed records of vax
16
Q
bacterial infections
A
-
bacterial placentitis
- ascending
- hematogenous
- nocardioform
- leptosporosis
- abortions caused by endotoxemia
17
Q
bacterial placentitis
A
- most common causes of equin abortion in US
- ascending: Streptococcus equi zooepidemicus, E. coli, K. pneumoniae, and P. aeruginosa
- nocardioform placentitis: Nocardioform actinomycetes
- Hematogneous (rare): Leptospira spp
- characteristic lesions on chorioallantois
18
Q
clinical signs of bacterial placentitis
A
- vaginal discharge
- premature mammary gland development
- abortion without warning signs
19
Q
dx of bacterial placentitis
A
- trans-rectal u/s: ascending
- trans-abdominal u/s: Nocardioform
- avillous areas
20
Q
tx of bacterial placentitis
A
- systemic abx (TMS, penicillin, gentamycin)
- altrenogest (regumate)
- NSAIDs
- Pentoxifylline
- long term tx throughout pregnancy
21
Q
infertility in mares
A
- ovarian tumors
- uterine abnormalities/infections
- anovulatory follicles
- developmental abnormalities
- abnormalities of the external genitalia
22
Q
ovarian tumors
A
- Granulosa-Theca Cell Tumor (GTCT or GCT)
- cystadenoma
- dysgerminoma
- teratoma (very rare)
23
Q
Granulosa-Theca Cell Tumor
A
- most common
- hormonally active
- benign
- unilateral enlargement of one ovary
- opposite ovary
- small, inactive
24
Q
clinical signs of GCT
A
- behavioral changes
- stallion-like responses
- aggression
- anestrus
- persistent estrus-nymphomania
25
dx of GCT
* **transrectal palpation**
* enlarged ovary
* lack of ovulation fossa
* **u/s**
* multi-cystic
* solid (very rare)
* **GCT diagnositc panel**
* **elevated inhibin (tell tale sign)**
* elevated testosterone
* baseline progesterone
* new endocrine test
* elevated AMH
26
tx of GCT
* **surgery**
* **remove abnormal overy**
* should start cycling
27
anovulatory/hemorrhagic follicles
* **may be confused with GCT!**
* **ovulation fossa-palpable**
* will spontaneously regress
28
contagious equine metritis
* **highly contagious bacterial venereal reportable disease** of horses caused by *T**aylorella equigenitalis***, a gram negative coccobacillus
* very strict regulations for import
29
transmission of CEM
* **venereal route**
* **contact with contaminated objects**
* **semen collection**
* doesn't survive in frozen semen
30
clinical signs of CEM in mares
* **intense neutrophilic endometritis/metritis**
* grayish-white discharge
* **short-term infertility**-few weeks
* **abortions- rare**
* **mares and delivered live foals** may become **carriers**
31
clinical signs/pathogenesis of CEM in stallions
* **no clinical signs** of CEM
* **local contaminant on external genitalia**
* **carrier** state
32
dx of CEM
* **swabs for culture**
* **mares**
* clitoral fossa, clitoral sinus, endometrium
* **culture all 3 sites on 3 sepearate days over 7 day period**
* **stallions**
* fossa glandis, urethral sinus, urethra, prepuce, penile body
* false negatives
* breed to two test mares
33
tx of CEM
* **only under supervision of state vet**
* 4% chlorhexidine and 0.2% nitroflurazone
* **quarantine for 21 days and negative serology**
