The New Mexico Livestock Board and the New Mexico Racing Commission are working with officials at Ruidoso Downs Race Track to ensure that equine herpesvirus-1 (EHV-1) is limited to the one racehorse confirmed positive late Friday (June 17).

The horse was euthanized on Friday night and the animal’s remains were disposed of off the track.

The barn in which the horse was located at the Ruidoso Downs, New Mexico, racetrack is under quarantine—no horses in, no horses out—following confirmation of neurologic EHV-1.

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