A 2-year-old filly stabled at Laurel Park has tested positive for equine herpesvirus, the Maryland Department of Agriculture announced yesterday. The filly, Nin, trained by King Leatherbury, was unable to stand Wednesday but was sitting up and eating well with no fever yesterday, according to the state Agriculture Department. Further test results confirming the diagnosis are pending from the University of Kentucky.
As a result of the presumptive positive test for equine herpesvirus (EHV-1), Laurel Park's Barn 1, where the filly is stabled, is under a hold order that restricts all movement into and out of the barn, including for training and racing, pending the results of more testing. The Agriculture Department took blood samples and nose swabs of selected horses in the barn that had come from out of state. Today, more testing will be done on horses near or linked to Nin. None of the other 29 horses that share Barn 1 has shown neurological signs of the condition.
There are about 800 horses stabled in approximately three dozen barns at Laurel Park. In a best-case scenario in which no other horses are found to have EHV-1, the hold on Barn 1 could be lifted by late next week, state veterinarian Guy Hohenhaus said. If other horses are diagnosed with the condition, the timetable would be extended.
"We're confident we have the barn in question under control," Hohenhaus said.
Georganne Hale, racing secretary for the Maryland Jockey Club, said racetracks in four states, Pennsylvania, New Jersey, New York and West Virginia, were prohibiting horses stabled at Laurel Park or Bowie Training Center from traveling to those places to race until the concerns in Maryland were resolved.
The virus causes upper respiratory infection and can cause severe neurological problems. The condition can be fatal to horses and can be spread by direct nose to nose contact, contaminated hands, equipment, food and water, and it can be carried in airborne droplets through a cough or sneeze up to 35 feet. There is no known human health risk associated with the virus.
Hohenhaus, in a statement, urged the horse community to maintain "diligence in continuing strong preventive measures." Those included keeping new horses separate from the general barn population for at least one week, disinfecting and keeping vaccinations up to date.
In January 2006, an equine herpesvirus outbreak that started at Pimlico Race Course and spread to Laurel Park, a farm in Kent County and the Fair Hill Training Center resulted in six horses being euthanized and 19 others becoming ill. The outbreak started Jan. 2, 2006, and the all-clear was sounded about two months later in early March.
During that two-month period, Pimlico was closed for training for 18 days, from Jan. 21 through Feb. 7, and three days of live racing were canceled at Laurel Park. Horses were prohibited from traveling from Maryland to other states.
"Today's news is disappointing but we have already put the proper precautions into place to control the situation," Hale said in a statement. "We learned a great deal from 2006 and now know to shut things down immediately if there is a possible case so as to reduce the possibility of it spreading. The one advantage to having this happen in Barn 1 is that it is already isolated from much of the backside."