An Anne Arundel County, Maryland, horse has tested positive for non-neuropathogenic equine herpesvirus-1 (EHV-1).

On the evening of April 2, the horse was transported to the Marion DuPont Scott Equine Health Center in Leesburg, Virginia. The animal exhibited severe neurologic signs and was euthanized shortly after arrival. The Virginia Department of Agriculture and Consumer Services’ Animal Health Laboratory, in Warrenton, Virginia, confirmed the horse had EHV on April 4.

The horse’s home farm is under a 21-day investigational hold and strict biosecurity measures are in place while Maryland Department of Agriculture inspectors perform additional epidemiological and infectious disease testing. The stable owner is contacting boarders and students. Epidemiological links to the sick horse are being notified of the situation and owners are cautioned to monitor horses at their premises carefully.

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (the neurologic form). In many horses, fever is the only sign of EHV-1 infection, which can go undetected