On June 3, officials at the Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA) confirmed a horse at a boarding facility in Durham County with the neurologic form of equine herpesvirus-1 (EHV-1). The 18-year-old Quarter Horse-cross gelding began experiencing clinical signs, including urinary incontinence, on that day and is reported as affected and alive. His vaccination status is unknown.

The horse has been isolated and is being treated at an equine referral hospital. The attending veterinarian and the farm manager have restricted movement of both horses and people onto and off the property and enacted strict biosecurity protocols that include twice-daily temperature monitoring of all horses at the facility. The number of horses exposed wasn’t reported. OMAFRA officials state there’s no link between the case at this facility and those at Woodbine Racetrack in Toronto or the Dufferin County farm that also recently experienced cases of equine herpesvirus myeloencephalopathy (EHM, the neurologic form).

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.

In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months) but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1