West Nile Virus (WNV) has been confirmed at a boarding facility in Parry Sound, Ontario. On August 21, 2026, a 5 year old mare developed neurologic signs including muscle fasciculations and mild ataxia. She is recovering with treatment. Her blood serum tested positive for WNV IgM. The horse was not vaccinated against WNV.
This is the second 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.