KENNETT SQUARE, Pa. - He still looks every bit the champion. Only the fiberglass casts on not one but both of Barbaro's hind legs are indicators of something terribly wrong.

“His ears are up, he's bright, he's looking around,” Dr. Dean Richardson said Thursday. “If you look at this horse, it'd be hard to put him down.”

That precisely is the heartbreaking task that could be imminent because of a hoof disease so serious Richardson said the Kentucky Derby winner is “a long shot” to survive.

“It could happen within 24 hours,” Richardson said during a news conference at the University of Pennsylvania's New Bolton Center.

Richardson said Barbaro has a severe case of laminitis in his left hind leg - a painful, often fatal disease caused by uneven weight distribution in the limbs.

“If he starts acting like he doesn't want to stand on the leg, that's it. That will be when we call it quits,” he said.

Richardson, who has treated Barbaro since the colt suffered catastrophic injuries in the Preakness on May 20, said 80 percent of the horse's left hoof wall was removed Wednesday with the sudden onset of the disease.