Neurologic EHV-1 Case Confirmed at University of Wisconsin

The Hoofer Equestrian Center (HEC) at the University of Wisconsin, Madison (UWM), voluntarily quarantined its lower barn on Feb. 8 after two horses housed there showed neurologic signs of equine herpesvirus-1 (EHV-1). Both horses were later euthanatized and one tested positive for EHV-1. One other horse housed in the same barn showed signs of the respiratory form of EHV-1, and several others had high fevers, according to Brea Ann Rogers, HEC barn manager. The center has horses in two barns, which are separated by a detached indoor riding arena.

Rogers said the first horse showed a fever on Thursday, Feb. 2. Other horses began spiking fevers over the following weekend. At first, veterinarians tested and treated them for strangles.

"By Monday, Feb. 6, we had seven other horses that had high temperatures," Rogers said. "That day we had one mare, which hadn't shown any previous signs, come down with the first neurologic signs."

Wednesday, Feb. 8, a UWM-owned gelding that had a fever previously developed neurologic signs.

"When the mare went neurologic, the vets thought she had something else, like EPM or rabies," Rogers said. At the time, they weren't thinking EHV-1. "It wasn't until the gelding came down with it that we realized what we were dealing with." Rogers said the gelding was brought to HEC in December, while the mare had been there for more than 1 1/2 years.

They transferred the gelding to the Veterinary Medical Teaching Hospital (VMTH) at the School of Veterinary Medicine within an hour of detecting his neurologic signs. He was euthanatized at the hospital on Feb. 10. Benjamin Darien, DVM, MS, Dipl. ACVIM, an associate professor of large animal internal medicine at UWM, tested the two neurologic cases. "One horse (the gelding) admitted to the VMTH was positive for EHV-1 isolation," Darien said. "The Wisconsin Veterinary Diagnostic Laboratory is conducting sequence analysis to determine if it is similar to Kentucky and Maryland (strains)."

The additional horse that showed signs of the respiratory form of EHV-1 also tested positive, Darien said.

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Chad Mendell

Chad Mendell is the former Managing Editor for .

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