Equine Surveillance in Canada

Creating awareness of equine health in Canada

Disease Alerts

Disease Date Location Status Description
Equine Herpes Myeloencephalopathy (EHV-1) May 29, 2020 Dufferin County Update

On May 27, 2020, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) was notified of the fourth confirmed cases of equine herpes myeloencephalopathy (EHM) due to equine herpes virus-1 (EHV-1) at a farm in Dufferin County.

This was the fourth horse on the farm to be confirmed with the disease between May 23 and May 27. Two of the horses have been euthanized due to severe and progressive neurological signs. The other two horses are receiving treatment at a referral hospital. A fifth horse on the farm was euthanized on May 23 due to severe and progressive neurological signs however testing to confirm EHV-1 was not conducted.

The farm manager along with the attending veterinarian restricted movement for horses and people on and off the property on May 17 and instituted strict biosecurity procedures at that time. The disease has been contained to the main barn on the property. The outbreak at this farm has an epidemiological link to a racing facility in the City of Toronto where an outbreak of EHM was first reported on May 18. Four horses from the racing facility were confirmed with EHM and referred to an equine hospital for treatment and a fifth horse, also presumed to have EHM, was euthanized.

The outbreak has been contained to a single barn.

EHV-1 does not pose a threat to public health or food safety.


EHV-1 infection is immediately notifiable by laboratories to OMAFRA under the Animal Health Act. 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.