The Equine Disease Communication Center (EDCC) reported Dec. 27 that a 2-year-old Thoroughbred gelding stabled at the Fair Grounds Race Course, in New Orleans, Louisiana, tested positive for the neurotrophic strain of equine herpesvirus-1 (EHV-1).

The horse, which had been at the track since Dec. 4, developed a fever without neurologic signs on Dec. 20, the EDCC said. The horse responded to systematic treatment until Dec. 25, when he developed neurologic signs. He was euthanized on Dec. 26 and transported to Louisiana State University for necropsy, the EDCC said.

“The horse was confined to its stall in Barn 14 since Dec 20 and had no direct contact with any other horses, but Barn 14, which houses 46 other horses, is currently under quarantine by the Louisiana State Veterinarian’s Office,” the EDCC said. “Horses will be monitored and have temperatures twice daily with increased biosecurity on the premises. An investigation with the State Racing Commission is currently underway.”

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). In many horses, fever is the only sign of EHV-1 infection, which can go undetected