West Nile Virus (WNV) has been confirmed in Simcoe County, Ontario. On July 25, 2026, a 5 year old Belgian gelding became acutely recumbent and was sent to a referral hospital for treatment but was euthanized due to worsening condition. West Nile virus was confirmed by PCR on brain tissue. This gelding was one of three horses on the property that had recently died with acute neurologic signs. The horse was not vaccinated against WNV.
This is the first 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.