It spread through the air, infecting horses one at a time; by June 8, 12 horses died from a deadly, mutated strain of equine virus. But as of right now, Wyoming horses still appear free of the disease.  

Vaccines for equine herpes protect horses from most strains of the disease. there are currently no reports of EHVM in the state (Photo: Seneca Flowers)

There were 421 horses at the National Cutting Horse Association’s Western National Championship in Ogden, Utah from April 30 through May 8. Thirty-eight of them were from Wyoming. 

Several horses, 88 as of June 8, were confirmed to have contracted the equine herpes virus Myeloencephalopathy, the neurologic form of Equine Herpes Virus-1, but only one from the Cowboy state was suspected of potentially having the disease.

The USDA Animal Plant Health Inspection Service defines EHV-1 as a “contagious viral disease of horses that can cause respiratory disease, abortion and occasionally neurologic disease.”

The neurological variant, EHVM, is a mutated form that currently has no vaccine, according to lecturer and University of Wyoming State Equine Extension Specialist Amy Mclean. She added that outbreaks like this sometimes spark research and development of such vaccines though.

Mclean said there hasn’t been a confirmed case in the state since the April-May outbreak occurred. 

Although humans cannot get the disease, they can transmit it to horses via clothing. The disease is generally spread through the air in its aerosol form.

Mclean said she didn’t feel the problem was a danger to UW as there were no horses in the program. 

She explained that the equine program on the university campus rarely used horses in the program as it is primarily textbook based. 

There will be a new course taught in the fall about equine health and diseases, which will include EHVM, she added.

Although the university does not have a horse farm, there has been one area under surveillance—the Cliff and Martha Hansen Teaching Arena. 

UW Livestock Farm Manager Dave Moore said he closed the arena for about three weeks during the initial EHVM scare, but he decided to reopen it after speaking with veterinarians who felt there was an improbable chance of the horses having the disease. 

“The reason we have reopened is it is primarily used by local people where in many instances the horses have never left the county,” Moore said. But if there were out of state horses there, he said the horse owners would have to provide veterinary proof the animals are free of the disease.

As of our publication date, there had not been any confirmed cases of EHVM in the state.

State Veterinarian Dr. Jim Logan said he felt the media coverage was a bit exaggerated. He said the disease was not new, as there was a previous outbreak of the EHVM in the state nearly ten years ago. 

“What made this particular outbreak significant is the number,” Logan said.

He said it is still a good idea for people to vaccinate their horses with the current Equine Herpes Vaccines. “Although they won’t stop all of them (Equine Herpes Virus strains), they will provide some pretty good protection.”

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