Equine Herpesvirus Reported in Northwestern Wyoming

Equine Herpesvirus Reported in Northwestern Wyoming

Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence.

Photo: Alexandra Beckstett, The Horse Managing Editor

Wyoming Livestock Board staff veterinarians announced Oct. 21 that neurologic equine herpesvirus type 1 (EHV-1) has recently been reported at two premises in northwestern Wyoming. According to an agency press release, one affected premises is located in Teton County and the other in Park County.

Thach Winslow, DVM, Wyoming assistant state field veterinarian for field operations, said via e-mail that eight horses on the Teton County property have shown signs of EHV-1, one horse has been euthanized, and one horse has tested positive thus far. A total of eight horses are currently under quarantine on two premises, he said.

Meanwhile, in Park County, Winslow said two horses have tested positive for EHV-1, 36 horses have been exposed, and a total of 38 horses are quarantined on four premises.

Winslow said the Teton and Park County cases are unrelated.

Although it's not transmissible to humans, EHV-1 is highly contagious among horses and camelids and is generally passed from horse to horse via aerosol transmission (when affected animals sneeze/cough) and contact with nasal secretions. The disease can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (EHM, the neurologic form). Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence.

In the agency press release, Wyoming State Veterinarian Jim Logan, DVM, said the state has seen cases of EHV-1 in past years, and there was a major outbreak of it nationally in 2011.

“This is not a new disease,” added Winslow in the release. “The risk for EHV-1 is always there because carrier horses cannot be identified. There is not a vaccine that is always effective in preventing the neurologic form of the disease, so the best prevention is good biosecurity.”

Logan advises horse owners to be vigilant of their animals and try to prevent nose-to-nose contact with other horses as nasal secretions can be a main source of transmission. They should also make sure their horses are not sharing water buckets and feed troughs. If your horse develops fever, respiratory problems, and/or neurologic signs, notify your veterinarian immediately.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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