Infected Laurel filly is euthanized

A 2-year-old filly trained by King Leatherbury at Laurel Park who had tested positive for equine herpesvirus was euthanized on Saturday night, according to Maryland agriculture officials, but no other horses at Laurel are showing signs of the highly contagious disease yet.

The filly, Nin, began displaying symptoms of equine herpesvirus, which attacks a horse's neurological system, on Wednesday. Although she had difficulty standing on Wednesday, she was back on her feet on Thursday. Her condition worsened over the weekend, however, according to the officials.

The barn where the filly was stabled is currently under a hold order, and no horses are being allowed to ship into or out of Laurel Park because of concerns about the disease.

Maryland agriculture officials said that as of Monday, five of the 25 remaining horses in the barn have tested negative, and that the other 20 results are pending. In addition, the 31 Laurel-based lead ponies - who mingle with more horses on the grounds than any others - have tested negative.

Laurel has been placed under restrictions three other times in the past two years because of concerns over equine herpesvirus.