Utah Department of Agriculture and Food (UDAF) officials released on Oct. 15 that one horse was confirmed positive with the neurologic form of equine herpesvirus (equine herpesvirus myeloencephalopathy, EHM) and nine horses were exposed. The positive horse, a gelding whose vaccination status was not reported, presented on Oct. 12 with ataxia (incoordination), fever, nasal discharge, and recumbency (down and unable to get up). He is reported as affected and alive.

Officials haven’t isolated the source of the disease, but the affected gelding competed at barrel races on Sept. 25, Oct. 2, and Oct. 5 at the Weber County Fairgrounds, in Ogden. Any horses that attended one or more of these events is considered potentially exposed. Officials advise their owners and/or handlers to isolate the horses, enact strict biosecurity procedures, and monitor the horses’ temperatures twice daily.

“We’re advising horse owners who have plans to attend events and competitions this season to practice diligent biosecurity,” said Chelsea Crawford, DVM, assistant state veterinarian, in a statement. “Limit or avoid horse-to-horse contact and use of shared communal water sources as much as possible, and disinfect shared equipment in between horses.”

EHV 101

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 EHM