State officials urge immediate precautions after serious form of equine herpes confirmed in local horse.

Organ Mountain News report

ALBUQUERQUE - State officials have confirmed New Mexico’s first case of equine herpes with neurologic complications in a horse located in Doña Ana County and are urging horse owners to take immediate preventive steps to limit potential spread.

The New Mexico Department of Agriculture and the New Mexico Livestock Board said the affected horse attended the 2025 Women’s Professional Rodeo Association World Finals and Elite Barrel Race in Waco, Texas, held Nov. 5-9. The animal has been isolated from other horses and is improving with supportive veterinary care.

The confirmed case involves equine herpesvirus-1, commonly referred to as equine herpes, which in this instance has developed into its most serious neurologic form, equine herpes myeloencephalopathy, or EHM.

The confirmation follows recent EHM cases reported in Texas and Oklahoma tied to equine events attended by horses from multiple states, including New Mexico.

Equine herpes is a highly contagious virus that affects horses, donkeys and mules. It spreads through respiratory secretions, shared equipment, trailers and contaminated environments. It does not infect humans but can cause respiratory illness, abortions, foal death and severe neurologic complications in horses.

Symptoms may include fever, nasal discharge, coughing, lethargy, hindlimb weakness, difficulty rising, loss of tail tone, urinary retention and in severe cases inability to stand.

“Immediate isolation and veterinary evaluation are the most effective tools we have,” said Dr. Samantha Holeck, state veterinarian. “Horse owners should closely monitor their animals and practice heightened biosecurity, especially if they recently attended events in Texas or Oklahoma.”

Veterinarians diagnose equine herpes through PCR testing of nasal swabs and whole blood. Officials emphasized that early testing and strict isolation remain critical in preventing further spread.

Although there is no cure, most respiratory cases recover with supportive care. Neurologic cases vary widely and severe paralysis carries a poorer prognosis.