A horse residing at the same facility as a Howard County horse that was recently diagnosed with non-neuropathogenic equine herpesvirus-1 (EHV-1) has tested positive for the same strain.

This second horse was tested as a result of a fever and EHV-1 diagnosis was confirmed by the Frederick Animal Health Laboratory. This second horse was euthanized for unrelated reasons.

All horses that were exposed to the two positive horses are currently free of clinical signs, appear healthy, and are being monitored daily. The farm will remain under quarantine to ensure the virus is contained. As of today (April 21), the Maryland Department of Agriculture believes the virus is contained to this farm and is not aware of any other EHV-1 cases in the state.

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