Neurologic Equine Herpesvirus in Lamb County, Texas

The Texas Animal Health Commission confirmed neurologic equine herpesvirus in a Quarter Horse from Lamb County.

The Texas Animal Health Commission confirmed neurologic equine herpesvirus in a Quarter Horse from Lamb County. iStock

The Texas Animal Health Commission (TAHC) received confirmation of equine herpes myeloencephalopathy (EHM), the neurologic disease linked to equine herpes virus (EHV-1), in a Lamb County Quarter Horse on January 10, 2022. This is the first positive detection of EHM in Texas this year.

The horse was tested after showing neurologic signs consistent with EHM. 

The premises has been quarantined, and TAHC staff are working closely with the owner and a local veterinarian to monitor the infected horse and enforce biosecurity measures on the premises.

“While the horse showed clinical signs, it was kept home until transferred to a local veterinary clinic for treatment,” said Dr. Angela Lackie, Assistant Executive Director of Animal Health Programs. “The horse traveled back home after clinical signs resolved.”

EHM is a neurologic disease of horses linked to the equine herpesvirus. Neurological signs appear as a result of damage to blood vessels in the brain and spinal cord. Clinical signs of EHM in horses can include: 

  • fever of 102°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 EHV-1 infection. If you suspect your horse has been exposed to EHV-1, contact your local veterinarian.

For more information on EHM please visit

To learn more about biosecurity measures owners can take to keep their horses healthy, visit

The equine industry is encouraged to obtain the latest information on equine disease events across the country on the Equine Disease Communication Center (EDCC) website, Subsequent Texas EHM cases will be posted on the EDCC.

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