From the Office of the State Veterinarian Regarding Equine Herpes Myeloencephalopathy (EHM)
- Hannah Dritt
- 19 hours ago
- 3 min read
Frankfort KY. - The Kentucky Department of Agriculture / Office of State Veterinarian (KDA/OSV) has received notification regarding the confirmation of several cases of equine herpes myeloencephalopathy (EHM), the neurologic disease linked to equine herpes virus (EHV-1) in both Texas and Oklahoma. The initial EHV-1/EHM horse was detected several days after the WPRA event finished. The affected horses both attended the 2025 WPRA World Finals and Elite Barrel Race event in Waco, Texas, Nov. 5-9, 2025. The second EHV-1/EHM confirmation occurred at an Oklahoma horse event Nov. 18, 2025. Additional participants of these events have been notified by animal health officials and are being monitored. Kentucky horses were reported to have attended one or both events but currently there are no known EHV-1/EHM detections in the Commonwealth associated with these events.
The extent of this EHV-1 outbreak is not fully known. Presentation of EHV-1 in these horses has been acute with rapid progression and high clinical severity. Measures to prevent further horses from direct or indirect EHV-1 virus contact are recommended. These measures, including increased biosecurity overall, are encouraged.
KDA/OSV encourages event sponsors of high-risk horse population (barrel/rodeo horses) related events to take all necessary precautions to prevent further spread of this virus and protect equine health. Given the nature of this virus and routes of transmission, and out of an abundance of caution, KDA/OSV recommends canceling or postponing equine events utilizing high risk equine populations (rodeo/barrel horses) as the best method to protect horses from further exposure until such time as the extent of the current outbreak has been determined. Mitigating risk of disease introduction is a shared responsibility that requires commitment from exhibitors, trainers, event managers, facility operators, veterinarians, and animal health officials.
“Equine owners are encouraged to stay vigilant and monitor exposed or suspect infected animals closely,” Agriculture Commissioner Jonathon Shell said. “Based on current evaluations and the evolving situation, we highly recommend equine owners take this virus seriously and weigh potential risks when commingling equine.”
Any owners of horses that may have been in contact with horses that attended these events or horses that may have otherwise been exposed to EHM should work with their veterinary practitioner to establish appropriate monitoring and diagnostic plans. These owners are also encouraged to take the following precautions:
When you return to your premises, isolate the horses that attended the event for at least two weeks.
Have the temperature of returning horses monitored twice daily for at least 14 days after last known exposure. If a fever (>102.5°F) or other signs consistent with EHM develop, contact your veterinarian.
Suspend hauling, showing, or mixing horses from the exposure group until further notice. Avoid taking exposed horses to other barns or events.
Disinfect boots, trailers, wash-racks, cross-ties, tie-areas, tack and tack rooms, buckets, grooming tools, and any shared equipment. Use an appropriate virucidal disinfectant.
Avoid sharing tack, halters, grooming equipment, buckets, water hoses, etc., between exposed and unexposed horses.
When doing feeding and chores, work with the returning horses last, wear boots and coveralls, and remove them before working with your other horses.
If any horse exhibits neurologic signs, coughing, or nasal discharge, isolate it immediately, wear protective gear, and call your veterinarian.
Keep accurate records: track which horses were present at events, their movement, and who handled them for contact tracing if needed.
Stay in contact with your local veterinarian and keep up to date on updates from state veterinary authorities.
Have laboratory samples for clinical horses submitted to an American Association of Veterinary Laboratory Diagnosticians (AAVLD) accredited laboratory. (e.g. - University of Kentucky Diagnostic Laboratory (UKVDL) or Murray State University -Breathitt Veterinary Center Laboratory)
Wash your hands.
Clinical signs of EHM in horses may include fever of 102.5°F or greater (fever most often comes before neurologic signs), nasal discharge, lack of coordination, hindquarter weakness, leaning or resting against a fence or wall to maintain balance, lethargy, urine dribbling, head tilt, diminished tail tone, and penile paralysis. It is important to remember these signs are not specific to EHM and diagnostic testing is required to confirm infection. If you suspect your horse has been exposed to EHV-1, contact your local veterinarian.
Additional resources for equine owners can be found here:
The equine industry is encouraged to obtain the latest information on equine disease events nationwide on the Equine Disease Communication Center (EDCC) website. Subsequent EHM cases related to these events will be posted on the EDCC.
Additional resources can be accessed through the sites noted below:
E.S. Rusty Ford
Equine Operations Consultant
Office State Veterinarian
KY Department Agriculture
502/782-5924