On October 12, 2017, the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) was notified of a confirmed case of Eastern Equine Encephalitis (EEE) in a horse in Bruce County.

The 12-year old unvaccinated mare with no travel history was euthanized following the sudden onset and progression of neurological signs. The horse was found down in the field, became unresponsive and was euthanized.

A post-mortem examination was performed at the Animal Health Laboratory in Guelph, Ontario and EEE was confirmed by testing of brain tissue.

EEE is a vector-borne disease spread by bloodsucking insects, usually mosquitoes, which transmit the virus from wild birds or rodents to horses.

Horses should be vaccinated against EEE every year. A three-way vaccine that protects against EEE, western equine encephalitis and tetanus is administered, typically in the spring.

To learn more about which vaccinations your horse should have, click here.