West Nile Virus (WNV) has been confirmed in the Regional Municipality of Peel, Ontario. On September 4, 2025, a 13 year old Rocky Mountain Horse mare was initially examined for lameness but then developed ataxia, hyperesthesia, and cranial nerve signs. She was sent to a referral hospital and is recovering. The horse was undervaccinated against WNV.
This is the sixth confirmed case of equine WNV in Ontario this year . To see past and present WNV cases in Ontario go to: https://www.oahn.ca/resources/ontario-equine-disease-alerts/ and enter the disease surveillance portal;