A 14-day quarantine of four barns has been reset at the Maryland track.
The Maryland Department of Agriculture's Animal Health Program has confirmed additional cases of EHV-1 at Laurel Park, it was announced March 19.
Following a positive test after a horse displayed neurological indications of the disease March 9, a second horse in the same barn began displaying clinical signs of EHV-1 and was confirmed positive March 15. That horse did not respond to treatment and has been euthanized.
After the second positive case, MDA Animal Health officials March 17 tested the remaining 20 horses housed in the same barn as the two positive horses. Those tests returned six positive results from asymptomatic horses. All positive horses have been removed from the barn and placed in isolated quarantine offsite.
A 14-day quarantine of four barns, determined by contact tracing, has been reset, and horses in the index barn will be retested prior to releasing the order. Horses stabled in quarantined barns are permitted to train during a 9:00 a.m.-10:30 a.m. window. Officials want interactions between the general horse population and affected barns limited as much as possible.
EHV-1, from the family of the equine herpesvirus, is a common DNA virus that can cause respiratory and neurological disease and abortion in pregnant mares. It can spread directly from horse-to-horse contact and can be passed to horses by humans from the use of contaminated clothing, tack, feed and water buckets, and equipment. The air around the horse that is shedding the virus can also carry it.
The department continues to work closely with Laurel Park and the Maryland Jockey Club to ensure that daily operations are able to continue as safely as possible with minimal disruption.
Laurel is also restricting movements from horses exiting its premises. Horses can continue to van into Laurel but they must remain onsite under the current two-week restriction, except for circumstances such as a horse making a return trip to Pimlico Race Course, another track in the state.
Owners are cautioned to monitor horses at their premises carefully and should contact their private veterinarians to arrange for EHV-1 testing if a horse exhibits significant temperature elevations or neurologic signs. Veterinarians are required to report equine neurologic syndrome to the department.