The University of Wisconsin-Madison School of Veterinary Medicine has very strong evidence that a horse treated and euthanatized at the university had the neurologic form of equine herpesvirus type 1 (EHV-1), according to a Feb. 14 memo that Benjamin J. Darien, DVM, associate professor in the veterinary school, sent to members of the Wisconsin Veterinary Medical Association.

The memo appeared Feb. 15 on the veterinary school’s web site. Darien wrote, “Our strong suspicion is based on the clinical signs of neurological disease exhibited by the patient and a high acute titer as determined by serum neutralization. Furthermore, polymer chain reaction (PCR) analysis on nasal swabs submitted to the University of Kentucky Livestock Disease Diagnostic Center for EHV-1 was also positive. Taken together, we are confident of the tentative diagnosis of EHV-1, but confirmatory results by virus isolation and histopathology are pending and may not be available until next week.”

The horse was admitted for treatment to the veterinary school on Feb. 8 and was humanely euthanatized on Feb. 10 due to progressive neurologic signs that were not responding to aggressive treatment. It was the second Wisconsin horse to be euthanatized for progressive neurologic signs during the last 10 days. The first horse was euthanatized on a farm, and ante-mortem serology demonstrated a high acute titer to EHV-1.

The School of Veterinary Medicine’s Large Animal Hospital strictly adheres to established sanitation, disinfection, and isolation protocols for potentially infectious and/or communicable diseases