Current Alerts 

Multi-State Equine Herpes Outbreak

We at Bristol Veterinary Service are aware of the multi-state outbreak of Equine Herpes Virus (EHV)/ Equine Herpes Myeloencephalopathy (EHM) in horses that attended barrel racing and rodeo events in Texas and Oklahoma in November. Several cases of EHM have been confirmed in Texas and Oklahoma, with reports of additional cases and equine deaths pending investigation.

Equine Herpes Virus: EHV‐1 is spread from horse to horse through contact with nasal discharge or spread as aerosolized droplets. Infected horses may not show clinical signs of the virus but may still spread disease. Horses can also contract the virus by coming into contact with contaminated surfaces such as stalls, water, feed, tack, and vehicles. People can spread the virus from horse to horse by contaminated hands and clothing. It is important for owners to watch for signs and symptoms and practice biosecurity measures.

At Bristol Veterinary Service, we continue to practice basic biosecurity between calls to keep all of our patients healthy and safe. Please be patient as we adapt to new information released and be advised that when scheduling appointments, we may be asking more screening questions to ensure we are practicing appropriate biosecurity measures. If you and your horse have traveled to any of the affected events listed below or have been in contact with any exposed or infected animals, please inform us when scheduling appointments.

For the most up to date information regarding confirmed cases, affected states, and biosecurity recommendations please click on the following links:

Equine Herpesvirus | Equine Disease Communication Center

American Association of Equine Practioners EHV Information

The Wisconsin DATCP’s website has EHV information and information on creating a biosecurity plan for equine events.

• Equine Herpesvirus
• Basic Biosecurity
• Biosecurity Resources for Events

Interstate Movement: Please note that many states may be implementing movement restrictions or new import requirements for equines during this outbreak. Please check with the state of destination to ensure that you are following their import restrictions.

New Equine CVI Requirements for Wisconsin: Due the current multi-state outbreak, Wisconsin is instituting new equine certificate of veterinary inspection (CVI) requirements. Effective Monday, November 24, all incoming CVIs (also known as health certificates) must include a statement regarding EHV-1 exposure.

At this time, horses that attended the following events are not eligible for movement to Wisconsin:

• WPRA World Finals at the Extraco Events Center in Waco, TX from November 5-9, 2025.
• BFA World Championship at Lazy E Arena in Guthrie, OK, scheduled for November 17-22, 2025.
• 377 Arenas Barrel Race in Stephenville, TX between November 10-17, 2025.

Horse Owners: If your horses traveled to Texas, Oklahoma, or other equine events where EHV exposure may have occurred, please contact us so we can provide instructions regarding isolation and monitoring.

• Exposed horses should be isolated for 21 days after last known exposure.
• Isolation includes preventing access to other horses and avoiding the sharing of equipment or personnel between exposed and non-exposed groups.
• Exposed horses should have a rectal temperature recorded twice daily.
• Clinical signs that should be reported to your veterinarian include: elevated temperature (above 101.5º), respiratory signs (nasal discharge, coughing), or clinical signs consistent with EHM (neurologic symptoms including inability to stand, difficulty walking, lethargy, and urine dribbling).

Upcoming Equine Events: Equine herpes virus can be spread by horses that are not showing any clinical signs, which increases risk for disease transmission during an EHV/EHM outbreak.

• Event Organizers: Consult with your event veterinarian and understand the risks associated with hosting equine events during a multi-state outbreak. Cancelling or postponing events may be necessary to stop the spread of disease.
• Horse Owners: Vaccinations are available for EHV-1 & EHV-4 which can help prevent respiratory and reproductive symptoms. There are no vaccines labeled for the prevention of the neurologic form of EHV-1 and vaccines should not be used on exposed horses. However, vaccinated horses may assist in limiting the spread of outbreaks of EHM by limiting viral shedding.”