The Equine Disease Communication Center (EDCC) reported May 13 that a horse residing in Palm Beach County, Florida, has been euthanized after testing positive for equine herpesvirus-1 (EHV-1).

“On May 12, one premises in Palm Beach County was placed under quarantine after a horse displayed neurologic signs and was confirmed positive for EHV-1 via PCR,” the EDCC statement said. “The 18 other horses on the premises currently are clinically normal. The index case has been euthanized for humane reasons. Biosecurity measures and twice daily temperature monitoring are in place. All states with traces have been notified. The Florida Department of Agriculture and Consumer Services will continue to monitor the situation.”

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 myeloencephalopathy (the neurologic form of the virus). 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 eight months), but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1