Q Does my mare need an equine herpes vaccination before I put her into foal? Peter Bright, Gloucestershire Donal says... The answer to this depends on numerous factors, including your mare’s previous vaccination status and your current husbandry procedures. To help answer though, it’s best that owners understand the equine herpes virus (EHV) and the problems and symptoms it can cause. The two main types, EHV-1 and EHV-4, are also the types we can vaccinate against. EHV-1 is the most significant viral cause of abortion in horses. However, it is more commonly known for the respiratory symptoms it can spark in young animals. In some cases, EHV-1 may even cause neurological signs, such as paralysis. The other type, EHV-4, usually causes mild respiratory disease. The disease is spread via direct or indirect contact, such as shared water troughs or via people’s hands and clothes. The symptoms in young animals are often snotty noses, fever, coughing and reduced appetite.
The standard vaccination programme is to give two primary vaccines four to six weeks apart, then booster vaccinations at six-month intervals. During pregnancy it is advised to vaccinate pregnant mares at five, seven and nine months of pregnancy. It is also advised to restrict contact between pregnant mares and young horses and/or show or performance horses. Horses coming on and off the yard should ideally be vaccinated too. Vaccination does not prevent infection fully, but significantly reduces the chance of it occurring, the severity and length of illness, and the incidence of abortion. It also assists in herd immunity.