Two states and one province have reported new confirmed equine herpesvirus-1 (EHV-1) cases within their borders 13 days after veterinarians began tracking an outbreak of the virus, which sometimes causes neurologic signs. The National Cutting Horse Association’s (NCHA) Western Regional Championship (held April 29-May8 in Ogden, Utah) is believed to be the point of origin for the outbreak, and animal health officials are still monitoring horses exposed at the competition closely.

Although it’s not transmissible to humans, EHV-1 is highly contagious among horses and camelids, and is generally passed from horse to horse via aerosol transmission (when affected animals sneeze/cough) and contact with nasal secretions. The disease can cause a variety of ailments in equines, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (EHM, the neurologic form). Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence.

New Cases:

At press time (5:00 p.m