In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. | Photo: Stephanie L. Church/The Horse

The Idaho State Department of Agriculture (ISDA) has received confirmation of an equine herpesvirus myeloencephalopathy (EHM), the neurologic form of equine herpesvirus-1 (EHV-1), diagnosis in a horse in Ada County.

The Equine Disease Communication Center reported that the 10-year-old Quarter Horse mare developed clinical signs on March 27.

The horse traveled from Arizona to Idaho in February and then was transported to the Salty Dash Futurity, in South Jordan, Utah, from March 15–17. The horse has not traveled to any other events or locations since returning to Idaho and is currently under veterinary care at a private facility, which is now under quarantine