A 21-year-old Thoroughbred gelding was euthanized after showing neurological symptoms of equine herpesvirus myeloencephalopathy (EHM), a severe form of equine herpesvirus-1 (EHV-1), during the HITS Culpeper Commonwealth National Horse Show in Virginia. The horse had been stabled in Barn 5, which, along with the gelding’s home barn in Loudoun County, was quarantined by the Virginia state veterinarian. Forty-two other horses in the affected barn were also quarantined and are being monitored with twice-daily temperature checks, while unexposed horses were allowed to continue showing without restrictions.

Following the positive diagnosis, event organizers and state officials held a meeting to discuss biosecurity measures and isolate cohorts from the affected horse’s farm. The show is continuing through Sunday under close supervision by the Virginia state veterinarian, the U.S. Equestrian Federation (USEF), and local veterinarians. USEF emphasized that decisions about continuing the event during an outbreak are made collaboratively based on exposure risk and biosecurity protocols, which are designed to minimize spread and protect unexposed horses.