A wave of concern is sweeping across the U.S. equine industry as a cluster of confirmed cases of Equine Herpesvirus-1 (EHV-1) has been linked to the Women’s Professional Rodeo Association World Finals and Elite Barrel Race event held November 5-9 in Waco, Texas. Since this event, EHV-1 infection has led to 15 confirmed cases of equine herpesvirus myeloencephalopathy (EHM) with seven cases in Texas, three each in Louisiana and Oklahoma, and one each in Colorado and New Mexico.
This number has doubled in the past 36 hours, according to case reports by the Equine Disease Communication Center.
EHV-1 is a highly contagious virus in horses that can cause respiratory and reproductive issues and neurological disease. It spreads among horses through direct contact with respiratory secretions, inhalation of aerosolized respiratory droplets (distances less than 30'), or contact with contaminated people or equipment.
With virus spread possible, it’s important to be vigilant with quarantining and reducing exposure. This includes preventing the movement of exposed horses, and avoiding sharing any grooming equipment, water and feed sources, or any other tools between infected and healthy horses. Also take care to change your clothes and thoroughly wash your hands and arms after working with infected horses. It is important to note that this virus can survive in the environment for several weeks.
Texas agriculture commissioner Sid Miller issued an alert earlier this week:
“The virus can spread fast, it can be deadly, and the earliest signs are often so subtle they’re easy to miss. That’s why monitoring your horses right now is critical. The quicker we identify a potential case, the better chance we have to protect not only our animals, but the entire Texas equine community.”
Monitoring for and Limiting EHV-1 Infection
The clinical signs of EHM include:
- Fever
- Incoordination or limb weakness (especially hind limbs)
- Urine dribbling
- Decreased tail or anal tone
- Inability to stand
Dr. Dusty Nagy, chief medical officer of the Texas A&M Large Animal Hospital, advises horse owners, trainers and practitioners to closely monitor their animals and check their temperatures at least twice daily. Fever is often the first indicator of EHM, but can it fluctuate through the day.
Nagy believes the numbers will only climb as the incubation period for the initial exposure increases.
“I do think that is probably an understatement for where we are right now as there’s a lot of testing pending,” Nagy says. “There are definitely horses out there that have been exposed, that are shedding, that appear healthy.”
To prevent further spread of this highly infectious virus, Nagy urges all horse owners to quarantine their horses.
“I recognize that there’s a lot of high end equine athletes that are involved in this, and this is a big time of the year for them. That’s a hard recommendation to take, but I do think the easiest way to stop or slow it down is to stop animal movement,” Nagy says.
