A second Maryland horse has tested positive for the equine herpesvirus (EHV-1). The horse was stabled at the same breeding facility as the Montgomery County index case diagnosed with the neurologic form of the disease, according to the Maryland Department of Agriculture (MDA).
The second horse remains at the breeding facility and has not shown symptoms. MDA tested horses that were in close contact with the infected horse at the breeding facility. That investigation led to the discovery of the second positive horse. Both are in isolation.
The index case was at the breeding farm for more than two weeks. The mare began showing neurological and respiratory symptoms on Tuesday, a day after returning home. A veterinarian reported the suspected case to MDA, as required by law. Lab tests confirmed the diagnosis.
EHV-1 symptoms may include respiratory disease, abortion, and intermittent outbreaks of neurologic disease in horses. Symptoms that should alert horse owners to the possibility of neurologic EHV-1 infection include fever, weakness, incoordination, and urine dribbling or inability to urinate. Horses with these symptoms should be examined immediately by a veterinarian.
All horses that were exposed to the two infected horses are currently free of symptoms and are being monitored. Both farms remain under quarantine. As of Friday, the department states it is not aware of any other cases of EHV-1 in the state.