The world's tallest dog is battling bone cancer that forced the amputation of one of his front legs.
Gibson stands 3 1/2-feet tall at the shoulder and is listed in the Guinness Book of World Records. The black and white great Dane from Grass Valley, Calif., stretches more than 7 feet tall when he stands on his hind legs.
Veterinarians found a tumor on Gibson's right front leg and had to amputate. The dog will also undergo chemotherapy. He was recuperating this week at his home in Grass Valley, a Gold Rush-era town 60 miles east of Sacramento.
Owner Sandy Hall says well-wishers from around the world have been asking how he is doing.
Gibson is a certified therapy dog and will soon return to work visiting veterans, sick children, burn victims and fellow cancer patients.