2 horses being watched after deadly virus found

New Zealand-bred euthanized, 16 others quarantined in Felton

December 13, 2008

• State officials said Friday they are closely monitoring two horses from a quarantined Felton barn in which a case of equine herpesvirus-1 was found earlier this month.

The two horses have been moved into an isolation facility away from Barn 1 at Dovington Training Center, where they had been stabled with Tintabella N, a 7-year-old mare who first showed signs of equine herpesvirus-1 on Dec. 3. When symptoms worsened last Sunday, the New Zealand-bred was euthanized.

According to a Delaware Department of Agriculture press release sent out Friday night, the two horses were part of a group of 16 quarantined in the barn after Tintabella N's death. On Wednesday, one of the two horses developed a fever and was moved into isolation. On Friday, the state learned that blood and nasal swabs from the horse tested negative for EHV-1. A repeat sample has been taken, and the results are expected within 48 to 72 hours.

"False negatives can occur, and a second confirmation of the negative will give us more confidence that the horse's fever is not due to EHV-1 infection," state veterinarian Dr. Heather Hirst said in the press release. She was not available for further comment Friday.

The second horse being monitored showed no clinical signs of the disease, but tested positive via a nasal swab. A blood sample tested negative, but the horse was also put in isolation and is being treated. No other horses are stabled at the isolation facility or on neighboring properties, state officials said.

According to Hirst, the 14 remaining horses in the quarantined barn tested negative for EHV-1 on both nasal swabs and blood samples.

Department of Agriculture spokesperson Anne Fitzgerald said Friday night that the quarantine of the Dovington barn will remain in effect for at least 21 more days. By law, the quarantine is 21 days from the last reported case. All the horses in the quarantined barn will be re-tested before the quarantine can be lifted.

Though New Jersey and Pennsylvania tracks have barred any horses from Dovington at their facilities, Dover Downs, the only Delaware harness track with an ongoing meet, has not banned horses from the non-quarantined barns at Dovington. Fitzgerald said she was not sure if that decision would be reconsidered in light of Friday's developments.

Tintabella N last raced at Harrah's Chester in Chester, Pa., on Nov. 24. Tintabella N had never raced or trained at Dover Downs.

Dover Downs harness racing manager John Hensley said track officials have great confidence in the decisions made by Hirst and the Delaware Harness Racing Commission.

Without proper containment, equine herpesvirus-1 can be deadly and wreak havoc on the racing community. In 2006, Maryland's thoroughbred racing industry came to a halt after an outbreak of the virus hit three Maryland tracks.

At the start of the outbreak, just two barns were put under quarantine at Pimlico. Within weeks, the Maryland Jockey Club put the entire track under quarantine after a horse in another barn at Pimlico became infected. Six horses died before the outbreak was brought under control.