The Equine Disease Communication Center (EDCC) has reported that a horse previously stabled at Parx Racing, in Bensalem, Pennsylvania, tested positive for equine herpesvirus-1 (EHV-1, also known as equine herpesvirus myeloencephalopathy or EHM).

The EDCC’s April 2 statement said the horse “with clinical signs of EHM” was being treated in isolation at a New Jersey equine veterinary hospital before testing positive for the neuropathogenic strain of EHV-1. The affected horse was subsequently euthanized.

“Two barns at Parx with exposed horses are currently under quarantine,” the EDCC statement said. “Updates will be posted as they become available.”

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (the neurologic form). In many horses, fever is the only sign of EHV-1 infection, which can go undetected