Before a mare can go to a stud, she needs to be tested for several diseases, each of which is notifiable to Defra (Department for Environmental, Food, and Rural Affairs). These diseases are Contagious Equine Metritis (CEM), Equine Infectious Anaemia (EIA) and Equine Viral Arteritis (EVA). Lets look at each in a little more detail…
Contagious Equine Metritis (CEM)
CEM is caused by a bacterium called Taylorella equigenitalis and it is very difficult to treat. 10-14 days after breeding with an infected stallion, the mare may begin to show symptoms if infection is acute. These signs manifest as grey to creamy vulvar discharge which mats the hair of the buttocks and tail, however, she may also show no symptoms. Stallions show no signs, the first and only symptom is that mares he services fail to become pregnant. The disease causes sub-fertility (cannot carry foal to term) and infertility in mares. She may spontaneously recover, however, will probably be a carrier for life.
The uterus may be infused with antibiotics such as penicillin and the external part of the reproductive tract cleaned with chlorhexidine solution, and nitrofurazone cream. In the stallion the penis, when extended fully may be washed with chlorhexidine solution, and dried, then nitrofurazone cream applied.
Equine Viral Arteritis (EVA)
This is caused by an RNA virus of the Arterivirus genus.
Symptoms manifest as
- oedema (abnormal fluid filled swelling)
- nasal discharge
- genital welling in both genders
- and, extremely unhelpfully (at a stud) all pregnant mares abort the foetuses!
- sudden death
- weak and/or irregular heartbeat
- abdominal and limb swelling
- enlarged spleen
- recurrent anaemia
- reccurrent fever
- penile enlargement in the stallion
- swelling of chest and legs
- Horses tire easily and cannot work
- recurrent fever and or anaemia
- may suffer acute or subacute relapses
Pregnant mares may abort, however may hold pregnancy to term. Foal may or may not be infected.
Diagnosis: Coggins test
Treatment: Euthanasia or quarantine for life
As you have seen, all these diseases are quite grim. Therefore, if your mare, or indeed stallion, is going to stud, have her (or him!) tested for these diseases, as calling the vet out to carry out a few tests saves potential heartbreak in the future.