The New Mexico Department of Agriculture and the New Mexico Livestock Board have confirmed the state’s first case of equine herpes myeloencephalopathy (EHM), a serious neurologic disease linked to Equine Herpesvirus-1 (EHV-1). Horse owners are urged to implement immediate preventive measures to safeguard their animals and mitigate potential outbreaks.
The affected horse, located in Doña Ana County, participated in the 2025 Women’s Professional Rodeo Association World Finals and Elite Barrel Race in Waco, Texas, from November 5 to 9. Following this announcement, the village of Corrales has canceled its annual Christmas de los Caballos All Equine Parade and Food and Toy Drive, which was scheduled for November 23. Currently, the horse is isolated and receiving supportive veterinary care, showing signs of improvement.
As more cases of EHM are reported, including recent confirmations from the Texas Animal Health Commission and the Oklahoma Department of Agriculture, the situation highlights the need for heightened vigilance among horse owners. These states reported cases on November 18, linked to equine events attended by horses from various states, including New Mexico.
EHV-1 is a highly contagious virus affecting horses, donkeys, and mules. It spreads through respiratory secretions, shared equipment, and contaminated environments. While the virus is not infectious to humans, it can lead to severe health issues in horses, including respiratory illness, abortions, and the neurologic condition EHM. Symptoms of EHM can manifest as fever, nasal discharge, lethargy, and in severe cases, paralysis and inability to stand.
Dr. Samantha Holeck, the state veterinarian, emphasizes the importance of immediate isolation and veterinary evaluation. “Horse owners should closely monitor their animals and practice heightened biosecurity, especially if they recently attended events in Texas or Oklahoma,” Dr. Holeck stated.
Veterinarians typically diagnose EHV-1 through PCR testing of nasal swabs and whole blood, providing accurate results crucial for effective management. State officials stress that early testing and strict isolation of any horse exhibiting signs of illness are vital to preventing further transmission of the virus. Although there is no cure for EHV-1, most respiratory cases recover with supportive care, while neurologic cases can vary significantly in prognosis.
To minimize the risk of infection, officials recommend that horse owners adopt several key practices. These include maintaining strict hygiene protocols, avoiding sharing equipment, and monitoring the health of their animals closely.
For further information, resources are available from the New Mexico Livestock Board, the New Mexico Department of Agriculture, the American Association of Equine Practitioners, and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service. Horse owners with questions regarding EHV-1 testing can contact the New Mexico Department of Agriculture’s Veterinary Diagnostic Services at 505-383-9299. For regulatory or livestock health concerns, they can reach the New Mexico Livestock Board at 505-841-6161. It is recommended that horse owners consult their veterinarians for guidance on diagnosis, treatment, and vaccination against EHV-1.
