The constant pounding Smarty Jones put on his hoofs in a brilliant racing career that brought him within one length of the Triple Crown, forced his retirement from the sport on Monday.

Diagnosed with bone bruises in all four hoofs, the winner of the Kentucky Derby and Preakness will stand stud at Three Chimneys Farm, occupying the stall of Seattle Slew, the only undefeated Triple Crown winner in history.

It's an appropriate spot for the red chestnut colt who recovered from a life-threatening accident early in his career and won every race until his last one when he was caught in the final furlong at the Belmont Stakes by Birdstone and finished a length behind.

Trainer John Servis had plans for the spunky 3-year-old who nearly died a year ago when he fractured his skull in a starting gate accident. But the persistent bruising problem caused him to be scratched from the Sept. 5 Pennsylvania Derby at Philadelphia Park, his home track.

Still, Servis hoped to run the horse in the Breeders' Cup Classic at Lone Star Park in Grand Prairie, Texas, on Oct. 30 with perhaps a warmup in either the Super Derby on Sept. 25 at Louisiana Downs, or the Pegasus in New Jersey in late September or early October. Those plans ended abruptly when a bone scan last Thursday revealed the chronic bruising problem.

Servis was heartbroken.

''It hurts me,'' the trainer said. ''He could do things so effortlessly. He might be the best of all time. It's unfortunate people won't see that. I know he's a great horse. I just hope it carries over to the breeding shed.

''He was an exceptional individual. It hurts but you have to move on.''

Dr. Larry Bramlage treated Smarty Jones and said the injury is the result of accumulated inflammation in the fetlocks which serve as a race horse's shock absorbers.

''We bring horses back from this all the time,'' Bramlage said. ''It's not a structural problem and the prognosis for full recovery is excellent. He needs to have an opportunity to move around in the field for a while. They have to have a break.''