Wisconsin Barn Quarantined; One Neurologic EHV-1 Case Confirmed

The Hoofer Equestrian Center (HEC) at the University of Wisconsin, Madison, voluntarily quarantined its lower barn on Feb. 8, after two horses housed at the facility showed neurologic signs of equine herpesvirus type-1 (EHV-1). Both horses were later euthanatized and one tested positive for EHV-1. One other horse housed in the same barn also 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 weekend. At first, attending veterinarians tested and treated the horses for strangles.

"By Monday Feb. 6, we had seven other horses that had a high temperature," Rogers explained. "That same day we had one mare, which hadn't shown any previous signs, come down with the first neurologic signs."
Wednesday afternoon, Feb. 8, a gelding that belonged to the University, which did have a fever previously, showed neurologic signs as well.

"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 herpesvirus. "It wasn't until the gelding came down with it that we realized what we were dealing with." According to Rogers, the gelding was brought to HEC in December, while the mare had been there for more than a year and a half.

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. However, he was euthanatized at the hospital Feb. 10.

Benjamin Darien, DVM, MS, Dipl. ACVIM, an associate professor of large animal internal medicine at the University of Wisconsin, 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.

About the Author

Chad Mendell

Chad Mendell is the former Managing Editor for TheHorse.com .

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