Alberta Confirms Case of Equine Herpesvirus EHV-1

The Office of the Chief Provincial Veterinarian has confirmed a new case of Equine Herpevirus-1 (EHV-1) in Alberta — a contagious virus that can cause serious neurological illness in horses known as Equine Herpesvirus Myeloencephalopathy. (EHM).

The affected horse, an 11-year-old gelding with no recent travel outside Alberta, developed sudden neurological symptoms, including difficulty moving and inability to urinate or defecate. The animal was admitted to an equine hospital and placed in isolation. Officials report that the horse is recovering and has regained basic functions, though mild neurological signs remain.

EHM is not a federally reportable disease in Canada; however, it is provincially notifiable in Alberta. This means veterinarians must report confirmed cases to the Official Chief Provincial Veterinarian, which monitors trends but does not impose quarantines or movement restrictions.

Alberta typically sees a small number of cases each year: four in 2023, one in 2024, and now one confirmed case so far in 2025.

Officials note that the affected horse was vaccinated annually for both EHV-1 and EHV-4. While vaccination can reduce severity and risk, it does not eliminate the possibility of illness. Strong biosecurity practices remain essential for all horse owners and boarding facilities. The home stable involved in this case is following general biosecurity guidelines.

Alongside Albera’s recent case, several EHM cases have been reported in the United States this fall. As of November 21, 16 cases have been identified, prompting some equine events to postpone or cancel activities to reduce transmission risks. Horse owners planning to attend events or shows stateside are encouraged to confirm event status and ask organizers about current biosecurity measures.

“Our rural horse community is experienced and resilient,” said Aren Skogstad, Lac Ste. Anne Agricultural Services Manager. “Cases like this are a reminder to strengthen biosecurity and keep an eye on our animals. A few simple steps go a long way in keeping barns and herds healthy.”

What Horse Owners Should Know:

• Monitor horses for signs such as fever, incoordination, weakness, or difficulty urinating/defecating.
• Keep vaccinations up to date while understanding that they do not guarantee full protection.
• Practice strict biosecurity, including minimizing horse-to-horse contact, avoiding shared equipment, and isolating any sick animals.

Resources and additional information are available through the
Government of Alberta , the Canadian Food Inspection Agency,
and the Equine Disease Communication Center.