Officials with the Kentucky Department of Agriculture said Thursday that test results have confirmed that horses that have fallen ill in three quarantined barns at Churchill Downs are suffering from equine herpes virus.
State Veterinarian Dr. Robert Stout had earlier said that illness was suspected to be the upper respiratory and neurologic ailment, but that diagnosis was based on clinical observation and could not be verified until test results were final."
"We have confirmed the diagnosis of equine herpes virus in all three barns," said Stout. "We know definitely what we're dealing with and now we can move on."
The tests that yielded the positive results include necropsies on two horses that were euthanized after exhibiting neurologic symptoms of the disease.
Stout said that all trainers and veterinarians connected to the horses in barns 6, 38 and 39 had been advised of the test results.
The three barns were placed under quarantine when a preliminary diagnosis pointed toward the presence of the virus. No horses in those barns are allowed to move in or out of those structures or mix with the general horse population at Churchill Downs. Symptoms of equine herpes virus most commonly include fever and an upper respiratory infection. The symptoms can also include lethargy, loss of appetite, a 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. The virus can be spread through the air, although it is short-lived and tests have shown that generally it travels only 35 feet. State agriculture officials say the disease poses no danger to humans. Churchill Downs has halted pre-race "milkshake" tests after the three barns at the track were placed under quarantine because of the cases of equine herpes virus.
Post-race milkshake tests on randomly selected horses will continue at the track. Churchill Downs had been performing blood tests on every horse prior to each race during its spring meet. Those horses had been required to report to the track's detention barn for the pre-race tests. Due to the contagious nature of the equine herpes virus, Churchill Downs officials decided to temporarily suspend those blood tests rather than place entrants in a confined space before each race.