A Standardbred racehorse residing in Genesee County, Mich., has tested positive for neurologic equine herpesvirus-1 (EHV-1), state veterinarian Steve Halstead, DVM, confirmed Jan 2.

Halstead told TheHorse.com that the affected horse participated in a race at Sports Creek Raceway, a haul-in only racetrack in Swartz Creek, Mich., on Dec. 22, 2012, and began showing neurologic signs of disease on Dec. 23, 2012. That day, the animal’s owner/trainer contacted their veterinarian, who took samples and sent them for evaluation at the state diagnostic lab, Halstead said. He was informed of the positive test results Dec. 28, shortly before 5:00 p.m., he said.

"(The horse’s condition) worsened through the first part of that week; in fact the veterinarian thought it was pretty much over on Wednesday (Dec. 26), but he since has recovered," Halstead said. "There’s one other horse in the same stable, but there’s no indication that it’s ill."

Halstead noted that both horses had previously received rhinopneumonitis vaccinations, "which is normal procedure for this veterinarian and this trainer. It wasn’t following infection, just a routine vaccination."

Halstead said both horses have been placed under quarantine, which will last at least 21 days.

The Sports Creek harness meet has concluded, Halstead said, and harness racing does not resume in Michigan until mid-January. Several harness racing tracks across the country, including The Meadowlands Racetrack in New Jersey and Balmoral Park in Illinois, have placed entry restrictions on horses that have raced at Sports Creek in recent day