Officials at Churchill Downs say a case of equine herpesvirus (EHV-1) confirmed in one horse should have limited impact on the fall meet that begins Sunday, as long as the disease is contained.

The Kentucky Department of Agriculture on Oct. 26 imposed a quarantine and ordered biosecurity measures on barn 47 after a 3-year-old trained by David Carroll tested positive for EHV-1. Under the quarantine, none of the 19 horses in Carroll’s section of the barn, including four that had been entered on the opening card, and none of 16 horses trained by Al Stall, Jr. stabled in the barn will be permitted to race or leave the barn. The quarantine period generally is 21 days.

“The results of tests administered so far have confirmed an equine herpes infection with neurologic involvement,” said Rusty Ford, equine programs manager for the office of Kentucky state veterinarian Dr. Robert Stout in a Churchill Downs release announcing the quarantine. “Those results suggest to us that we are dealing with an animal that has a low level of the virus in its system, and that works to our advantage. If that is the case, the infected horse would present a lesser risk of transmission of the virus to other horses in the barn or the general horse population.”

Symptoms of EHV-1 most commonly include fever and an upper respiratory infection. The symptoms can include lethargy, loss of appetite, nasal discharge, and a cough. In severe cases, horses can suffer a loss of coordination and an inability to stand. The illness can be fatal