It is Equine Herpesvirus. There are a number of types. The most prevalent one is responsible for the respiratory form of the disease which is most prevelant especially among youngstock ( and TBs). Many studs (most i think) require proof of vaccination against this disease before accepting your mare onto the stud property. Main clin signs are nasal discharge, fever, decreased appetite.
There is also the more serious neurologic form. EHV is an endotheliotropic disease - meaning it attacks the blood vessel walls and causes its damage through this mechanism. Signs can include ataxia or paralysis, epistaxis, seizures or sudden death.
Initially 2 vaccines are admin 4-6weeks apart. Thereafter 6mthly boosters are admin and these must be recorded on your horses' passport. Pregnant mares should be vaccinated at the 5th, 7th and 9th month of pregancy to prevent EHV abortion.
