Yesterday evening, the Maryland Department of Agriculture (MDA) Animal Health Program issued a statement confirming two unrelated cases of Equine Herpesvirus Myeloencephalopathy (EHM) in Maryland. According to MDA, both horses developed clinical symptoms over the weekend and were confirmed positive for EHM on Monday, March 8. The horses were stabled in two different counties (Anne Arundel and Cecil) with no known connection.
The horse in Anne Arundel County was stabled at Laurel Park and displayed clinical symptoms on Saturday, March 6. The horse was sent to the Marion duPont Scott Equine Medical Center in Leesburg, VA where the wild-type strain of Equine Herpesvirus (EHV-1) was confirmed. EHV-1 is the virus that causes EHM. Currently, the horse is still at the medical center and is responding well to treatment.
MDA has placed four barns at Laurel Park on a hold order, prohibiting movement on or off the premises until any exposed horses have been cleared for release. The hold order is a precaution for any horses that were potentially exposed to the positive horse. As of Tuesday (March 9) evening, no other horses were showing clinical signs. Horses under the hold order will be closely monitored for any clinical signs, and any horses showing clinical signs will be tested immediately. MDA Animal Health staff is working closely with Laurel Park to ensure that their daily operations are able continue as safely as possible.
The horse in Cecil County is stabled at a private facility and began displaying clinical signs of EHM on Friday, March 5. According to MDA, this horse did not respond to treatment and was euthanized on Saturday, March 6. Samples from the deceased horse were confirmed positive for EHM on Monday, March 8. This barn has also been placed on a hold order with veterinary professionals monitoring the remaining horses. The hold order remains in place until all exposed horses have been cleared for release.
MDA asks owners to monitor horses at their premises carefully, and contact their private veterinarians to arrange for Equine Herpesvirus testing if a horse exhibits significant temperature elevations or neurologic signs. Veterinarians are required to report equine neurologic syndrome to the department by calling the Animal Health Program at (410) 841-5810.
The Maryland Jockey Club issued a statement earlier this morning confirming they had been, and still are, in contact with MDA in relation to the horse that was stabled at Laurel Park.
Dr. Dionne Benson, 1/ST Racing’s Chief Veterinary Officer stated, “Upon notification of the diagnosis, the Maryland Jockey Club, again per standard veterinary protocol, immediately closed the backside prohibiting horses from leaving the stable area.
“Thanks to the contact tracing efforts of the veterinary team, I can confirm that the ill horse had recently been in two different barns and other horses in those two barns had contact with horses in two additional barns. Out of an abundance of caution for all other horses on-site, the Maryland Jockey Club quarantined barns 1, 4, 10 and 11. These barns are now under strict monitoring and quarantine requirements, including separate training from other horses at Laurel Park, prohibition from racing for horses from these barns, and increased biosecurity protocols. The team at the Maryland Jockey Club is working with the Maryland State Veterinarian, the Maryland Racing Commission, and the Maryland Thoroughbred Horsemen’s Association to ensure all mandated biosecurity protocols are strictly followed.”
“As has been reported, the backside at Laurel Park will remain closed to horses shipping out for at least two weeks from the notification date, March 8, and live racing is cancelled for Friday, March 12. Pimlico Race Course will also be subject to the same restrictions on horses leaving the stable area.
“As of this morning, no additional cases of EHV1 have been identified at the Maryland Jockey Club. The 1/ST Racing veterinary team will continue to monitor this situation closely and will provide additional updates as they become available and are relevant.”
The Equiery will continue to monitor the situation and update our readers as additional information is released from MDA and/or MJC.