Three horses succumbed to neurologic illness and were euthanatized at the Columbia Horse Center (CHC) in Columbia, Md., last week, according to the animals’ attending veterinarian. Two more horses at the facility developed signs of the yet-unidentified disease, but are recuperating well, he added. The Maryland Department of Agriculture (MDA) reported on March 30 that rabies has been eliminated as a potential diagnosis on the deceased horses, and that more test results should be available by the end of the week.

Fred T. Lewis, DVM, a private practitioner based in Clarksville, Md., treated the cases at the CHC. About 60 horses are kept at the CHC, which is a hunter/jumper lesson, boarding, and show facility.

Lewis said that the first horse, a 28-year-old mare, developed neurologic signs and was euthanatized the afternoon of Wednesday, March 23. The second case to be put down, a 26-year old gelding, had a fever and was off his feed earlier in the week, but appeared to have recovered. But by Thursday afternoon, March 24, he had become severely neurologic and the decision was made to euthanatize him.

Lewis said, “I called the state, because we had something unusual. They’re testing for everything we can test for.” On recognition of the second case, CHC staff began taking temperatures of all horses at the facility at set times throughout the day and employed strict disinfection measures between areas of the facility, while restricting the people coming on and off the grounds. These restrictions remain in place. Shows and lessons were cancelled and boarders were asked to stay off the grounds