Equine herpes myeloencephalopathy has been confirmed in the City of Toronto, Ontario. A 3 year old Thoroughbred gelding used for racing was referred to an equine referral hospital on June 17, 2025 after developing acute hindlimb ataxia. He tested positive for equine herpesvirus 1 (EHV-1) by PCR on a sample of whole blood (negative on nasal swab). His condition in stable. The affected gelding was vaccinated against EHV-1. Another horse, headed to a retirement facility, was exposed to this gelding during transport, however, given the gelding was not shedding from the nose at the time the exposure is believed to be low risk. Following good biosecurity practice, however, the horse has been isolated at the retirement facility and will be monitored, under veterinary supervision, for 14 days. In total, 63 horses were exposed to the confirmed case.

As per the racetrack's biosecurity protocol, the remaining horses in the barn were tested on June 19, 2025 and were negative at that time . Animal movement restrictions, with scheduled exercise, along with biosecurity protocols will remain in effect for the index barn until further risk assessments (monitoring and testing) are completed. Please refer to the following news release from the Alcohol and Gaming Commission of Ontario for further details.