EHV-1 Reported in Barrel Horses near Stillwater, Minn.

EHV-1 Reported in Barrel Horses near Stillwater, Minn.

Photo: Stephanie L. Church, Editor-in-Chief

Five horses on premises around Stillwater, Minn., have tested positive for equine herpesvirus-1 (EHV-1) after showing signs of neurologic disease. Most of the infected animals either competed at area barrel racing events in recent weeks or resided on properties with horses returning from such events.

In a March 20 posting on Stillwater Equine Veterinary Clinic's (SEVC) Facebook page, representatives of the practice reported that two barrel horses located north of Stillwater tested positive for EHV-1 on March 7, and one was euthanized. On March 17 another barrel horse began showing clinical signs consistent with EHV-1 and veterinarians collected samples for testing; those results are pending, and the horse is slowly recovering.

According to the SEVC Facebook postings, on March 18 one barrel horse was euthanized at the University of Minnesota after displaying neurologic signs and testing positive for EHV-1. That same day another was examined for EHV-1-like signs and is undergoing veterinary treatment; test results on that horse are pending. As of March 20, a Wisconsin pony exposed to barrel horses at a Stillwater-area farm and displaying EHV-1-like clinical signs was euthanized after veterinarians deemed its blood test histopathology consistent with the disease.

"At this time we are recommending that barrel horses do not travel to shows until these tests are completed and the extent of this outbreak can be determined," the SEVC Facebook post read.

Health Alert: Equine Herpesvirus

EHV-1 is highly contagious among horses and can cause a variety of ailments, 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 limbs, and incontinence.

The Minnesota Board of Animal Health recommended in a March 20  release that owners keep horses with fevers and clinical signs of contagious respiratory infection at home and not take them to shows, clinics, or public trail rides. "Horse owners should also be aware that transportation of horses to competitions, shows, and clinics may increase the risk of exposure to infectious organisms," the board said in the release. "Owners of affected horses should wash and disinfect their hands and change their clothes before coming into contact with healthy horses to prevent the potential spread of these infectious organisms." will provide updates on the situation as it develops.

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