Editor's note: On April 15 the Maryland Department of Agriculture released the following statement:
A horse stabled in Montgomery County has tested positive for the mutant neurotropic form of equine herpesvirus type 1 (EHV-1) and is being treated by a private veterinarian.
The horse had been outside Montgomery County for breeding for more than two weeks before returning home on Monday. The horse began showing mild respiratory and neurological signs on Tuesday and was seen by a private veterinarian, who reported the suspected neurological illness to the Maryland Department of Agriculture (MDA), as is required by law. Laboratory tests conducted by MDA confirmed the diagnosis. The horse’s condition is improving.
Other horses at the farm are now being tested as are horses that were in contact with the ill horse at the breeding facility. Those results will not be available until tomorrow. Both farms are presently under a 28-day investigational hold while MDA inspectors perform additional epidemiological and infectious disease testing.
Stables near the one where the sick horse resides have been notified of the situation and owners cautioned to monitor horses at their premises carefully.
MDA’s Animal Health Program is monitoring the situation closely. Owners should contact their private veterinarians to arrange for EVH testing if a horse exhibits significant temperature elevations or neurologic signs. Veterinarians are required to report equine neurologic syndrome to MDA.