STICKNEY, Ill. – A seventh horse has died after contracting the equine herpesvirus that has been circulating on the Hawthorne backstretch since mid-October. The horse, trained by Mike Stidham, died Monday, Dec. 24, Illinois state veterinarian Dr. Dawn Folker-Calderon confirmed Thursday. Its remains have been sent to the University of Illinois for a necropsy, but the EHV-1 virus is all but certain to be confirmed as the cause of death. The horse already had tested positive for the virus and since sometime last week had displayed the neurologic symptoms associated with the disease’s most serious form. Stidham had all 22 of his Hawthorne-based horses tested for EHV-1 earlier in December. The 15 that tested negative were moved to a private quarantine facility in Texas, while the seven positive horses – including the fatality – were isolated in Barn 8 at Hawthorne. The isolation occurred Dec. 12, which is the starting date for the Hawthorne quarantine clock. If 28 days pass without a new horse testing positive and displaying EHV-1 symptoms, Dr. Mark Ernst, chief veterinarian for the Illinois Department of Agriculture, will review and potentially lift the Hawthorne quarantine. As of Thursday, the quarantine review date is set for Jan. 9, but even a lifting of the Illinois quarantine on Hawthorne doesn’t guarantee horses can leave the track for other racing venues. Tampa Bay Downs already has said no Hawthorne horses will be allowed to ship in during this racing season. Other tracks, including Fair Grounds and Oaklawn Park, are not allowing horses who have been based at Hawthorne to enter their stable areas until further notice. Hawthorne’s fall-winter meet ends Dec. 30. The progression of EHV-1 in the horse that died Dec. 24 followed a different pattern than in previous fatal Hawthorne cases. First came the positive test; days later, neurologic symptoms developed, but instead of quickly succumbing – as had happened in previous fatal cases – the horse appeared to be recovering. Folker-Calderon said that on Sunday the horse could move its legs and was eating; on Monday, it suddenly declined. Stidham’s 15 departed horses are among about 80 animals that have been permitted to leave the Hawthorne grounds for approved off-track quarantine facilities. Sixteen horses remain in isolation on the Hawthorne backstretch, Folker-Calderon said.