As of May 26, there are no new clinical equine herpesvirus (EHV-1) cases among horses at the Columbia Horse Center in Maryland. The facility has been handling an outbreak of the neurologic form of the virus since late March. During the week of May 22, one horse that had been diagnosed with the virus more than a month prior had to be euthanatized. While the mare had been responding well to treatment, she took an unexpected turn for the worse. Veterinarians, Maryland animal health officials, and farm operators continue to work together to bring the situation to a close.

There remains no reason to believe that the virus has moved off of the farm and all preventive measures remain in place–including a Maryland Department of Agriculture “hold order” prohibiting horses from moving on or off of the farm. Because the mare euthanatized the last week of May had not been shedding virus for several weeks, state officials still expected to lift the hold order on June 10.