November 20, 2025
Equine Herpesvirus Type 1 Outbreak in Nearby States
Horses at recent events in Texas and Oklahoma should be closely monitored.
(JEFFERSON CITY, Mo.) – Multiple cases of Equine Herpes Myeloencephalopathy (EHM), the neurologic form of Equine Herpesvirus Type 1 (EVH-1), have been confirmed in Texas and Oklahoma following equine events in these states. Currently, there are no confirmed cases in Missouri.
The first cases were confirmed in horses that attended an equine event in Waco, Tx., Nov. 5 - 9. Two additional cases were confirmed in horses that attended a barrel racing event in Guthrie, Ok., earlier this week. Owners of horses at either event should consult with their veterinarian as well as isolate and quarantine the horses for at least 14 days.
“Missouri owners or trainers of horses at either of these events should closely monitor their horses for at least 14 days from last exposure, monitor temperature twice daily and isolate them from other horses” said Missouri State Veterinarian Dr. Steve Strubberg. “EHV-1 is highly contagious in equine and can spread very quickly.”
EHV-1 is spread directly through nose-to-nose contact and infected animals can release particles when they cough or sneeze. Indirect transmission is also possible through shared water or feed buckets, tack and travel in the same trailer.
Horse owners should increase biosecurity measures and monitor their horses for symptoms, including fever, nasal discharge and cough, stumbling, hind end weakness or any neurological issues. If you notice any symptoms, contact your veterinarian immediately. Cases that show neurological issues are considered a medical emergency.
There is no risk to humans from EVH-1 or EHM.
For more information about Equine Herpesvirus Type 1, visit the USDA equine herpesvirus website.
For more information about the Missouri Department of Agriculture, visit the Department online at Agriculture.Mo.Gov.