Equine herpesvirus 1 (EHV-1) has been confirmed in an 18 year old gelding, in Simcoe County, Ontario, with 15 other horses exposed. On June 6, 2026, the gelding developed edema of all four limbs. His signs progressed to acute hindlimb ataxia and bladder paralysis and he was taken to an equine referral hospital that day. He became recumbent on June 8 and was euthanized. The horse was vaccinated against EHV-1. Nasal swab was positive for EHV-1 by PCR.
The facility owner, working with their veterinarian, has instituted voluntary animal movement restrictions and biosecurity protocols. To see past and present EHV-1 neurologic (EHM) cases in Ontario go to: https://www.oahn.ca/resources/ontario-equine-disease-alerts/ and enter the disease surveillance portal;