Lecture 23: Disorders of the Gravid Uterus

- average of 7-9% and range of 5-20%

- often older mares, barren mares, or foal heat breedings

What is the incidences of abortion like in horses?

- transcervical

- hematogenous

- previous intrauterine infection

What are the 3 routes of bacterial infection?

- transcervical infection leading to abortion

What is the route of infection if the lesion is at the cervical star?

- mares typically present 7-9 months of gestation

- inappropriate lactation

- vulvar discharge

what are the clinical signs of placentitis?

- Ascending

- nocardioform

- hematogenous

What are the 3 forms of placentitis?

- caused by step. Equi zooepidemicus

- starts at cervix and impacts near the cervical start

- see abortion at any stage, highest incidence between 5-10 months gestation

What is ascending placentitis?

- nocardioform actinomycetes or Crossiella equi

- see late term abortions, stillbirths, premature birth

What is nocardioform placentitis?

- At base of gravid uterus and non-gravid horns or body/horn

- Chorionic surface = brown, sticky, and mud-like mucoid/purulent at uterine tubule junction

- Aborted mares will clear the infection

What are the characteristics of nocardioform placentitis?

- caused by lepto, mare reproductive loss syndrome, and salmonella

- see widespread placental infection

What is hematogenous placentitis?

- combine thickness of the uterus and placenta (CTUP)

- presence of purulent material between uterus and placenta

- culture vaginal discharge

How do you diagnose placentitis?

- double dose of altrenogest (regumate)

- broad spectrum abx (potassium penicillin + gentamicin)

- flunixin meglumine (banamine)

- pentoxifylline (helps fetus)

What is the gold standard standard treatment for placentitis?

- EHV-1 = most important cause of herpes abortion

- EHV-3 = coital exanthema --> vesicles not abortion (pic)

- EHV-4 = rhinopneumonitis and sporadic abortion, resp in young horses

What are the 3 types of herpes virus?

- transmission = inhalation or contact with aborted fetus or placenta

- carriers occur due to latency

- associated with stress, new groups during late gestation, yearlings housed close to mares

What is the transmission of equine herpesvirus like?

- late abortion - 7 months to term with no clinical signs

When do you see abortions with equine herpesvirus?

- Virus --> tonsils and lymph nodes --> viremia --> lungs, endometrium, chorioallantois, fetus, nervous tissue --> damages endometrium --> edema --> choriallantoic separation --> fetal anoxia --> late abortion - 7 months to term with no clinical signs

What is the pathogenesis of herpesvirus?

- outbreaks of abortion preceded by resp outbreak in foals/yearling 1-4 months earlier

- more sporadic

- eosinophilic intranuclear inclusion bodies in foci in liver, ect

What is a typical EHV clinical picture?

- EHV-1

you always need to consider _______ on farms 1st when mares are aborting

- early recognition (isolate, clean, PPE)

- separate yearlings + pregnant mares

- vaccinate = EHV-1

How do you prevent EHV?

- (3), 5, 7, 9 months gestation

When should you vaccinate mares for EHV-1?

true

True or false

stress can be a cause of abortion

- death in absence of bacterial infection

- mares not systemically ill

What is foal mummification?

- loss of fetal fluid

- uterus contracted around fetus

- secondary to twins

How does foal mummification occur?

- dead fetus with bacterial contaminations --> soft tissues often removed

- mares not systemically ill

What is fetal maceration?

- rare due to dorsal uterine attachment of broad ligament

- mid to late term (5-10 months)

- most limited to 180* rotation

- signs can vary from no pain to colic, restlessness, ect

What are uterine torsions like in horses?

- may not cause pain

What are

- painful

- creating low grade colic that does not response well to analgesics

What are >180* uterine torsions like in horses?

- rectum palaption --> uturus might feel constricted

How do you diagnose uterine torsions in horses?

- standing flank laparotomy

- rolling the mare with a plank in her flank

How do you correct uterine torsions in horses?

- vaginal varicose veins

- more common in older, multiparous mares near the end of gestation

What is the most common cause for vaginal bleeding in horses?

- ligation, cautery, and laser ablation

- preparation "H", works great sometimes

How do you treat vaginal varicose veins?