Two additional horses at Hawthorne Race Course in Cicero, Ill., were moved to an isolation barn area Oct. 26 after testing positive for equine herpesvirus (EHV-1), a track official reported.

Those horses, plus one that had a fever Oct. 25 and was also moved to the restricted barn area, are responding to treatment, according to Jim Miller, Hawthorne’s assistant general manager. Miller updated the Illinois Thoroughbred Horsemen’s Association on the situation via memorandum following a meeting with horsemen on the morning of Oct. 26.

The affected horses have been moved to Barn K2 to be monitored. The latest horses to test positive were housed in Barn K1. The Oct. 25 case was from Barn C, Miller reported.

The Illinois Department of Agriculture has not placed a formal quarantine on Hawthorne, meaning horses may still ship into the grounds under certain conditions. All horses, except in cases of emergency, are required to remain on the grounds while exit restrictions are in place