The Maryland Department of Agriculture (MDA) today (Feb. 27) at 5:20 p.m. announced that test results taken last week from 16 more Maryland horses involved in the equine herpesvirus-1 (EHV-1) situation in Maryland and Virginia, for a total of 28 negative tests. As a result of these negative tests, eight of the 13 properties of interest are being fully released from hold orders; three of the properties have “conditional or partial” releases prohibiting individual horses of interest from leaving the property; one property (in Carroll County) remains under a hold order because test results are still outstanding; and one property remains under a hold due to a positive test result. Maryland uses “Hold Orders” to prohibit the movement of horses on to or off of a given property.

Since returning from the Marion duPont Scott Equine Medical Center in Leesburg, Va., the horses at the three conditionally/partially released properties (one each in Charles, Howard, and Carroll Counties) have been isolated with strong biosecurity measures. Those horses remain under a hold order, while the others on those properties have been released.

Test results from one mare that was euthanized last week in Harford County were positive for EHV-1. The mare had come from Virginia through Leesburg for treatment and was located at a facility in Harford County to recover. The facility has been under a hold order with no horse movement on or off the farm since the investigation in Maryland began early last week. There are no horses on the facility with any signs of EHV-1. 

MDA is acting on the side of extreme caution and reminds Maryland horse owners that it is always prudent to practice on-farm biosecurity to prevent illness of any kind. MDA takes this situation very seriously, with a policy not to wait for test results to place a hold order