The Texas Animal Health Commission (TAHC) received confirmation of a case of equine herpesvirus myeloencephalopathy (EHM, or neurologic herpesvirus) in a hunter/jumper horse visiting Texas from Wyoming.
The EHM-positive horse traveled to Katy, Texas, to participate in a hunter/jumper event that began on January 29. The infected horse has not visited any other events in Texas.
The infected horse was immediately isolated and quickly relocated to a Brazos County veterinary hospital for care after showing signs of ataxia and other neurologic signs consistent with EHM.
Horses that were known to have come in direct contact with the infected horse were in an isolated area of the facility, and the directly exposed horses are now under quarantine and veterinary monitoring.
"TAHC veterinarians are in direct contact with event organizers to ensure participants are notified and enhanced biosecurity measures are being taken," said Dr. Susan Rollo, Texas State Epidemiologist. "I believe the attentiveness and quick actions taken by the event veterinarian and staff will help contain the disease and mitigate the risk of spread."
Owners of horses that attended the event are encouraged to take precautions, including the following:
- Clean and disinfect tack, boots, equipment, and grooming supplies.
- When you return to your farm, isolate the horses that attended the event for at least two weeks.
- Have their temperatures monitored twice daily for at least 14 days after last known exposure. If a fever or other signs consistent with EHM develop, contact your veterinarian.
- When doing feeding and chores, work with the returning horses last, wear boots and coveralls, and remove them before working with your other horses.
- Don’t forget to wash your hands.
Owners should work with their veterinary practitioners to establish appropriate monitoring and diagnostic plans for any potentially exposed horse(s).
For more information on biosecurity measures you can take to keep your horses healthy, visit this page.
One of the most common clinical signs of EHV-1 is fever, which often precedes the development of other signs. Respiratory signs include coughing and nasal discharge. Neurologic signs associated with EHM are highly variable, but often the hindquarters are most severely affected.
Horses with EHM might appear weak and uncoordinated; urine dribbling and loss of tail tone might also be seen. Severely affected horses might become unable to rise.
For more information on EHM please visit this page.
It is important to remember that these signs are not specific to EHM and diagnostic testing is required to confirm EHV-1 infection. Many horses exposed to EHV-1 never develop clinical signs. If you suspect your horse has been exposed to EHV-1, contact your local veterinarian.
The equine industry is encouraged to obtain the latest information on this outbreak and other disease events across the country by visiting the Equine Disease Communication Center (EDCC) website.
Any additional Texas EHM cases will be posted on the EDCC.