Equine herpesvirus type 1 (EHV-1) has been confirmed as the cause of illness in three Thoroughbreds that were stabled in a training barn at Turfway Park in Florence, Ky. Tuesday’s announcement follows treatment of several EHV-1 outbreaks in Ohio and Pennsylvania since January.

The EHV-1 organism can cause three different forms of disease, including rhinopneumonitis (a respiratory disease often affecting young horses), abortions in pregnant mares, and neurologic disease. Horses in the Ohio and Pennsylvania outbreaks showed fevers, respiratory illness, and neurologic deficits. In the Kentucky cases, horses have shown fevers, and two of the horses showed neurologic signs several days later. There are at least seven other strains of equine herpesviruses. Horses can survive the neurologic form of EHV-1 with supportive care, but if a horse becomes recumbent (stays down), it is difficult to nurse the horse back to health. The virus doesn’t live long in the environment, and it can be killed with bleach