Toby Keith has issued a statement on his website saying that he "hated to cancel and disappoint my fans" after a severe case of laryngitis forced him to back out of the Big Valley Jamboree in Cambrose, Alberta, Canada, on Sunday (July 31). Keith said he was following his doctor's advice. "I even went to the venue hoping to perform, but it was impossible," he wrote. Ronnie Dunn, who was also performing at the festival, extended his set in Keith's absence. Keith will resume his Locked & Loaded tour on Thursday (Aug. 4) in Sacramento, Calif.