- EVA is a contagious disease. Although EVA can be a systemic illness, it is often only found on breeding premises. Venereal transmission of EVA can occur not only by natural mating but also by Al using fresh, chilled or frozen semen. The infection is spread by contact with infected horses or aborted foetuses.
- Clinical Signs
- The viral infection can cause fever, depression, and oedema (swelling) especially of the limbs and inflammation around the eyes. The virus may cause abortion in pregnant mares and severe respiratory disease and death in young foals.
- The virus localises in a stallion’s sex glands and the virus may be shed in his semen for several weeks, months or years afterwards and possibly for life.
- Protection
- A vaccine is licensed for use in horses in the UK and has been used widely in thoroughbred stallions to provide some immunity against EVA.
- The protective efficacy of this vaccine has not been demonstrated in the face of a field outbreak.
- EVA is a preventable disease by adherence to the Industry Code of Practice.