In many horses, the only sign of EHV-1 infection is fever, which can go undetected. | Photo: Kevin Thompson/The Horse

The Ontario Ministry of Agriculture, Food, and Rural Affairs has been notified of a confirmed case of equine herpes myeloencephalopathy (EHM), caused by equine herpesvirus-1 (EHV-1), in a Simcoe County horse.

The horse developed acute and severe neurologic signs of disease and was euthanized. Another horse that shared the paddock with the infected horse also developed neurologic signs but is recovering. The farm owner has voluntarily placed the premises under a self-imposed quarantine to reduce the risk of viral spread.

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