Currently an outbreak of the reportable disease Equine Herpesvirus Type 1 (EHV-1) and its neurologic form Equine Herpes Myeloencephalopathy (EHM) is occurring in the United States in horses that attended or were exposed to attendees of November 2025 events in Texas and Oklahoma. 

The Cornell Animal Health Diagnostic Center (AHDC) offers several tests to diagnose clinically sick horses with EHV-1 and EHM, and has prepared guidance materials for veterinarians around said testing.

Read the guidance online