The Minnesota Board of Animal Health (MBAH) has reported that a horse in Scott County has tested positive for equine herpesvirus myeloencephalopathy (EHM), the neurologic form of equine herpesvirus-1 (EHV-1).

In a statement on the organization’s website, the MBAH said the horse was stabled at Dark Horse Farm in Prior Lake.

"The horse became ill on Friday, Feb. 6," the statement said. "It exhibited neurological signs including ataxia (incoordination) and urinary incontinence. It was then moved to Cleary Lake Veterinary Clinic in Prior Lake where it was held in isolation for treatment until test results were completed. Infection with equine herpesvirus type 1 (EHV-1) was subsequently confirmed by polymerase chain reaction tests performed at Cornell University. The horse was euthanized on Thursday, Feb. 12."

The MBAH has placed the other horses residing at the affected horse’s home stable under a quarantine for at least 21 days. Those animals will be monitored closely for fever or other signs of EHV-1.

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and EHM. In many horses, fever is the only sign of EHV-1 infection, which can go undetected.

In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around 8 months), but can be earlier. Abortions can occu