Lecture 8 Flashcards
Definition of abortion
Expulsion of a non viable fetus and its membranes between 50 and 300 days of gestation
*before this is early embryonic death and after this is still birth
What are the main causes of equine abortions?
Twin pregnancies
Umbilical cord torsion
Viral, bacterial, or fungal infections
Digestion of large amount of eastern tent caterpillars
What causes umbilical cord torsion?
Excessively long umbilical that twists and restricts blood flow
What are two viral agents that cause abortions?
Equine rhinopneumonitis (herpes 1)
Equine viral arteritis
- both of theses are reportable diseases
What does EHV-1 cause?
Resp disease, neurological disease, abortion
How is EHV 1 transmitted?
Respiratory, contact with infected tissue, placenta, fetuses, or fluids
What is special about EHV 1
The virus stays viable for several weeks in the environment
What does EHV1 cause?
Late abortions
“Abortion storms” in unvaccinated horses
How to diagnose EHV1?
Necropsy- foci of liver and edematous lungs
Histopathology- eosinophilic inclusion bodies
Virus isolation
PCR
How to treat or prevent EHV1?
No treatment
Prevent by vaccinating mares during months 5,7, and 9 months of pregnancy
What is equine viral arteritis?
Is carried by stallions and causes abortions in mares
How is EAV transmitted
Respiratory or venereal
What is special about EAV?
Can survive in frozen semen
What are clinical signs of EAV?
Fever, lacrimation ,nasal discharge, and edema of legs, ventral abdomen, and/or scrotum
what are the repro consequences of infection with EAV?
The mare that is infected by the carrier stallion will not loose that pregnancy…but she will transmit the virus to mares in late gestation who will abort
Fetuses aborted from EAV are usually what?
Partially autolyzed
May also develop pneumonia in utero
How to diagnose EAV?
Send blood and semen to approved lab
How to prevent EAV?
Test all breeding stallions once a year
Vaccinate- difficult because horse must be isolated for 21 days and has to be approved by the state veterinarian
What are bacterial causes of abortions
Bacterial placentitis (ascending, hematogenous, nocardioform) Lepto Abortions caused by endotoxemia
What is the most common cause of equine abortion in the US
Bacterial placentitis
What agents cause ascending placentitis
S. Zooepidemicus
E. Coli
Klebsiella pneumonia
Pseudomonas
What causes nocardioform placentitis
Nocardioform actinomycetes
What causes hematogenous placentitis
Leptospira
What are clinical signs of bacterial placentits?
Vaginal discharge
Premature mammary gland development
Abortion without warning signs
Increased CTUP and placental separation on ultrasound
How to diagnose nocardioform placentits
Ultrasound- transabdominal
Pus on US
Unlike ascending placentitis, cervix will be fine
What will you see grossly on the placenta with cases of bacterial placentitis
Avillous areas
How to treat bacterial placentitis
Systemic antibiotics (TMS, penicillin, gentamicin)
Altrenogest (regumate)
NSAIDs
Pentoxifylline
What are infertility problems in mare?
Ovarian tumors Anovulatory follicles Developmental abnormalities Abnormalities of external genitalia Uterine abnormalities/infections
What are ovarian tumor types?
Granulosa theca cell tumor
Cystadenoma
Dysgerminoma
Teratoma
What is the most common ovarian tumor
Granulosa theca cell tumor
What is granulosa theca cell tumor?
Hormonally active, benign
Unilateral enlargement of one ovary
The opposite ovary will be small and inactive
What are clinical signs of GTCT
Behavioral changes- stallion like responses, aggression, anestrus, persisten estrus
How do diagnose GTCT
Transrectal palpation- enlarged ovary, lack of ovulation fossa
US- multi cystic, solid (rare)
Elevated inhibin, testosterone, and AMH
Normal progesterone
How to treat GCTC
Surgery- remove entire affected ovary and mare returns to cycling
What is contagious equine metritis
Highly contagious venereal reportable disease
What causes CEM
Taylorella equigenitalis- gram negative coccobacillus
How is CEM transmitted
Venereal route
Contact with contaminated objects
Semen collection
CEM clinical signs in mare
Intense neutrophilic endometritis/metritis
Short term infertility
Rare abortions
Gray/white discharge
CEM clinical signs in stallions
No clinical signs
Local infection on penis
Develop carrier state
How to diagnose CEM in mare
Swabs from clitoral fossa, clitoral sinus, and endometrium
**must culture these three times on three separate days over one week
How to diagnose CEM in stallion
Swab fossa glandis, urethral sinus, urethra, prepuce, penile body
Cultures may be falsely negative
Breed to two test mares
How to treat CEM
Report to state vet
Quarantine for 21 days
Clean and pack
