The Maryland Department of Agriculture is conducting a neurologic equine herpesvirus-1 (EHV-1) investigation in six locations in Maryland, including five horses currently located in the state.

The investigation is warranted because these horses had possible indirect exposure to an EHV-1 test-positive horse initially under treatment for colic at the Marion duPont Scott Equine Medical Center in Leesburg, Va. The five Maryland horses were discharged before the horse in Leesburg showed clinical signs of EHV-1.

The “index” horse that originally went to Leesburg was from St. Mary’s County, Maryland (the sixth location being monitored) and remains under treatment at Leesburg.

MDA veterinarians are going to the six Maryland locations this afternoon to put weeklong “investigational hold orders” on the farms to prevent any movement of horses onto or off of the farms until test results are back. MDA veterinarians will evaluate each location on a case-by-case basis. MDA is acting on the side of extreme caution.

For more information on EHV-1, check out our free PDF library of EHV-related articles including images, or all our archived EHV-1 articles on TheHorse.com.