Two Additional Utah Horses Confirmed EHV-1 Positive

Two Additional Utah Horses Confirmed EHV-1 Positive

Photo: George P. Allen, PhD

Two additional Cache County, Utah, horses have tested positive for equine herpesvirus-1 (EHV-1), bringing the total number of confirmed cases in that state to four, according to a Feb. 27 update from the Utah state veterinarian's office.

"Tests on two of three horses that were under observation returned positive results on Wednesday at 11:00 a.m [MST]," the statement read. "One other horse remains under observation. It will be retested in the coming days. The number of confirmed or suspect cases remains at five."

Two of the five horses have been humanely euthanized because of their condition. The office confirmed the first two confirmed cases on Feb. 26.

On Feb. 27 Utah State Veterinarian Bruce King, DVM, told The Horse that all the horses involved in the current outbreak have exhibited neurologic signs and fevers.

Several quarantines are currently in place in Cache County. Additionally, The Cache County Fairgrounds horse arena has closed until further notice, as it is believed that most of the sick horses had been at the facility within the past week.

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 equines, 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. Should a horse that potentially has been exposed to EHV-1 display any of the aforementioned clinical signs, call a veterinarian to obtain samples and test for the disease. will continue to provide updates as more information becomes available.


Related Content:

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.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More