Texas Horse Tests Positive for Neurologic EHV-1

The Quarter Horse from Parker County is the state’s first confirmed case of EHM this year.
Please login

No account yet? Register


Texas Horse Tests Positive for Neurologic EHV-1
The Quarter Horse from Parker County is the state’s first confirmed case of EHM this year. | Photo: Wikimedia Commons
On March 25, Texas Animal Health Commission (TAHC) officials received confirmation of equine herpesvirus myeloencephalopathy (EHM), the neurological form of equine herpesvirus-1 (EHV-1), in a Parker County Quarter Horse. The horse was tested after showing neurological signs of EHM.

“The positive horse has not recently attended any events or known to have come in direct contact with horses from other premises,” said Andy Schwartz, DVM, the state veterinarian and TAHC executive director. “Since EHM is transmitted through direct horse-to-horse contact, short-distance aerosol or contaminated tack, we believe the risk for disease transmission is very low.”

Officials have quarantined the horse’s premises and TAHC staff, the local veterinarian, and the owner are working closely to maintain biosecurity measures on the premises and to monitor the affected horse.

This case marks the state’s first confirmed case of EHM in 2021.

EHV 101

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and equine herpesvirus myeloencephalitis (EHM, the neurologic form).

equine herpesvirus
VIDEO | Health Alert: Equine Herpesvirus

In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months) but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with EHM usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

Herpesvirus is easily spread by nose-to-nose or close contact with an infectious horse; sharing contaminated equipment including bits, buckets, and towels; or clothing, hands, or equipment of people who have recently had contact with an infectious horse. Routine biosecurity measures, including hygiene and basic cleaning and disinfection practices, should be in place at all times to help prevent disease spread.

Current EHV-1 vaccines might reduce viral shedding but are not protective against the neurologic form of the disease. Implementing routine biosecurity practices is the best way to minimize viral spread, and the best method of disease control is disease prevention.


Written by:

Diane Rice earned her bachelor’s degree in agricultural journalism from the University of Wisconsin, then married her education with her lifelong passion for horses by working in editorial positions at Appaloosa Journal for 12 years. She has also served on the American Horse Publications’ board of directors. She now freelances in writing, editing, and proofreading. She lives in Middleton, Idaho, and spends her spare time gardening, reading, serving in her church, and spending time with her daughters, their families, and a myriad of her own and other people’s pets.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

What signs does your horse show when he has gastric ulcers? Please check all that apply.
1 vote · 1 answer

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!