On January 5, 2023, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) was notified of a confirmed case of equine herpes myeloencephalopathy (EHM), caused by equine herpesvirus-1 (EHV-1) infection, at a premises in the Region of Waterloo.

A mature mare was examined and treated by a veterinarian after presenting with incoordination, which rapidly deteriorated. The premises is under veterinary supervision, including biosecurity protocols, and voluntary movement restrictions have been implemented by the facility manager.

EHV-1 infection is immediately notifiable by laboratories to the Office of the Chief Veterinarian for Ontario under the Animal Health Act, 2009. Attending veterinarians concerned about potential cases of EHV-1 infection may contact an OMAFRA veterinarian through the Agricultural Information Contact Centre at 1-877-424-1300.