Harford County (Map, News) - A Harford County horse was found with a neurological strain of equine herpes virus and was euthanized as a state-led pursuit of infected horses draws to a close.

The Maryland Department of Agriculture was first notified of the outbreak by the Marion duPont Scott Equine Medical Center in Leesburg, Va. Veterinarians found the equine herpes strain in mid-February, when a horse from St. Mary’s County that was being treated for colic tested positive for the virus, said Sue duPont, a spokeswoman for the department.

In response, the department tested 30 horses in eight facilities that may have been in contact with the horse. The Harford County horse was the only one found with a positive result.

The horse, which had trouble standing and walking properly due to the virus, was euthanized, and the small facility, with 15 surviving horses, is under quarantine, said Guy Hohenhaus, veterinarian for the department.

The department would not release the name of the facility.

“I’m not panicked or anything like that,” said Richard Norling, owner of Deer Creek Farm in Darlington, which boards horses in Harford County. “This is basically an alert to use caution when moving horses on and off farms.”

The St. Mary’s County horse probably caught the virus from the Harford County horse when they were both being treated at the Leesburg medical center, Hohenhaus said.

However, “there is no sign of any additional sick horses,” Hohenhaus said.

The neurological strain of equine herpes can be spread by contact between horses or through objects that have come in contact with an infected horse. The virus attacks the horses’ brains and can result in death. Horses that are infected can have trouble walking, standing and holding their head straight.

Two other facilities in the state are remaining under quarantine, though tests came back negative, because the departments want to be sure that enough time goes by before they are released.

lgreenback@baltmoreexaminer.com