The Equine Disease Communication Center (EDCC) reported Feb. 13 that three mares on a single facility in Bannock County, Idaho, have tested positive for the neurologic strain of equine herpesvirus-1 (EHV-1).

“Three Quarter Horse mares showed an onset of clinical symptoms including fever, ataxia, and neurological symptoms,” the EDCC said. “Two of the affected mares were euthanized. The premises is under quarantine and strict biosecurity is being followed. The epidemiological investigation is ongoing.”

The EDCC reported that this is the fourth Idaho premises to be quarantined due to EHV-1 in 2018.

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 equine herpesvirus myeloencephalopathy (the neurologic form). In many horses, the only sign of EHV-1 infection is fever, which can go undetected