Equine herpes myeloencephalopathy (EHM) has been confirmed in Grey County, Ontario. On October 24, 2024, a 20 year old mixed breed gelding showed acute neurologic signs that progressed rapidly to recumbency then seizures. The horse was euthanized. EHM was confirmed on October 29, 2024. Three additional horses were exposed. The facility owner has voluntarily stopped animal movements and is working with their veterinarian to implement biosecurity protocols.
Equine herpesvirus 1 (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.