Minnesota EHV-1: Two Horses in Stable Condition

Two horses are in stable condition while being treated for neurologic equine herpesvirus-1 (EHV-1) at the University of Minnesota (UM) Large Animal Hospital, according to the treating clinician. Both animals--who reside at the same Wright County, Minn., farm--have tested positive for the virus since being admitted to the clinic this week. A third horse (the index case) from the same premises was euthanized after showing signs of disease.

Treating clinician Anna Firshman, BVSc, PhD, CERP, Dipl. ACVIM, ACVSMR, assistant clinical professor of Large Animal Medicine at the UM Veterinary Medical Center, told TheHorse.com that one horse began showing signs of neurologic disease suddenly on Nov. 10; the animal's condition deteriorated rapidly, she said, and the decision was made to euthanize him.

Shortly thereafter, a second horse began to show clinical signs associated with EHV-1 and was admitted to the UM Large Animal Hospital on Nov. 11, Firshman said. Diagnostic tests soon confirmed EHV-1. The final horse began showing clinical signs not long after and was admitted to the hospital on Nov. 14, she relayed.

"A rapid genetic test was used to test for EHV-1," she said. "Results are already back and are positive for the virus."

The horses' clinical signs have included severe weakness, ataxia (incoordination), and an inability to urinate and defecate, she added.

"The horses are being cared for by a designated care team including internal medicine specialists, to focus on the intensive care needed for patients," she said. "The horses are stable currently but time is need to know the full outcome."

Firshman noted that because the index farm has been closed to on- and off-farm horse transportation for at least six months, "there is very little chance that additional horses have been exposed as part of this outbreak."

Additionally, she said, the horses were brought directly into isolation at the university's Large Animal Hospital, which is not in the same vicinity as UM's Leatherdale Equine Center and Piper Performance Clinic.

"The college is unique in having two separate facilities for equine care, one half mile apart," she explained. "All cases suspected of having EHV-1 are isolated and being cared for at the Veterinary Medical Center's Large Animal Hospital in special facilities designed for neurologic, infectious patients. This allows a designated care team to focus on the intensive care needed for patients suspected of having infectious diseases and separate staff dedicated to protect the health of patients seen at the college's Leatherdale Equine Center."

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.