Notice of Equine Herpesvirus-1

On November 8, an 11-year-old gelding with no history of travel outside of Alberta or Canada developed acute neurologic signs, ataxia, inability to urinate or defecate, and was diagnosed with EHM. The horse was admitted to an equine hospital where it was placed in isolation. The horse is recovering and has regained its ability to urinate and defecate but is still exhibiting mild neurological signs. The horse has been vaccinated annually with a vaccine that contains both EHV-1 and EHV-4 components. This demonstrates that while vaccination may impart some protection in some horses, the risk of clinical disease still exists for individual or groups of vaccinated horses. Strict biosecurity measures are another tool to prevent introduction and spread of EHV-1 and the horse’s home stable is following American Association of Equine Practitioners General Biosecurity Guidelines.

Read the Full Notice Here- EHV-1 Notice November 2025,

Resources for Veterinarians and Horse Owners:

• Government of Alberta Equine herpesvirus-1
• Canadian Food Inspection Agency Equine herpes myeloencephalopathy (EHM) fact sheet
• Texas Animal Health Commission Equine herpes myeloencephalopathy Fact Sheet

Useful Links:

• Office of the Chief Provincial Veterinarian
• Reportable and Notifiable Disease Regulation
• Canadian Animal Health Surveillance System
• Equine Disease Communication Center