11/21/2025
Some updates on the EHV-1/EHM outbreak. This information is from NYS Ag + Markets. They will continue to put out information as they receive it. I want to remind people that there are *currently* no cases in NY, however, as horses are shipped around the country that may change.
The New York State Department of Agriculture and Markets, Division of Animal Industry, has been made aware of an outbreak of Equine Herpes Virus (EHV)/ Equine Herpes Myeloencephalopathy (EHM) in horses that were at or associated with barrel racing and rodeo-type events in Texas and Oklahoma. Several cases of EHM have been confirmed in Texas and Oklahoma associated with these equine events, with numerous reports of additional cases and equine deaths pending investigation. This is a very fluid situation, so it is best to check verified sources for information (state departments of agriculture websites, EDCC when available).
We do not have any confirmed cases of EHV/EHM in New York at this time. Our office is coordinating with the affected states and we are currently awaiting to receive trace information from Texas and Oklahoma. If we receive traces from the other states, we will contact those owners directly and issue quarantines to mitigate further spread of the disease.
****This outbreak serves as a reminder of the potential disease risks associated with large commingling equine events. It underscores the importance of timely reporting of diseases and ensuring that movement requirements are followed, including veterinary inspection and health certificates prior to travel****
Horse Owners: If your horses traveled to Texas, Oklahoma, or other equine events where EHV exposure may have occurred, please contact our office directly at [email protected] . We will provide guidance regarding isolation and monitoring:
Exposed horses should be isolated for 21 days after last known exposure.
Appropriate isolation includes restricted access to other horses, avoiding the sharing of equipment or personnel, and utilization of protective barrier precautions.
Exposed horses should be monitored twice daily for elevated temperature (above 101.5*), respiratory signs (nasal discharge, coughing), and for clinical signs consistent with equine herpes myeloencephalopathy (neurologic symptoms including inability to stand, difficulty walking, lethargy, and urine dribbling).
If elevated temperature, respiratory signs, or EHM-compatible clinical signs are noticed, contact your veterinarian.
Upcoming equine events: Equine herpes virus can be shed for prolonged periods of time, including in clinically healthy horses, which increases risk for continued disease spread during an EHV/EHM outbreak.
Event Organizers: We recommend you consult with your veterinarian and understand the risks associated with hosting equine events during a multi-state outbreak. Cancellation or postponement of events may be important to stop continued spread of disease. If events do take place, we recommend short-timed health certificates within 72 hours and increasing biosecurity practices on site.
Horse Owners: We recommend that you consult with your veterinarian on the risks associated with travel to upcoming equine events. EHV is a ubiquitous virus and commonly present in the environment, so biosecurity measures are paramount to decreasing potential for disease transmission.