NEONATAL EQUINE HERPESVIRUS TYPE-1 INFECTION ON A THOROUGHBRED BREEDING FARM

Of 17 foals born on a Thoroughbred breeding farm between March and Apr il 1995, infection with equine herpesvirus type 1 (EHV-1) was associat ed with neonatal morbidity in 5 foals, 3 of which died or were euthani zed. Morbidity and mortality were associated with pulmonary inflammati on, and EHV-1 was identified in the lungs of the 3 foals that died. Al l neonatal EHV-1 infections occurred in foals of mares housed in the s ame pasture and barn. No other clinical manifestations of EHV-1 infect ion (eg, abortion, neurologic disease, or respiratory disease) occurre d during this outbreak. Three foals were treated with acyclovir (1 die d, 2 survived), which may have influenced the clinical outcome in the surviving foals.