American racehorse Big Brown is being retired to stud after suffering a career-ending injury.

The dual-classic winning horse injured his right front foot while at work yesterday (13 October) morning on Aqueduct’s turf track in New York.

He tore off part of his off fore when it caught on his back hoof while running.

The 3-year-old colt was preparing for the £5million Breeders Cup Classic on 25 October at Santa Anita, California, where he was due to go head-to-head with US Horse of the Year Curlin.

Big Brown has won 7 from 8 starts — including the Kentucky Derby and Preakness Stakes. But he surprised racing followers when, while making his bid to become the first Triple Crown winner since 1978, he trailed in last in the Belmont Stakes in June.

He was found to have a crack in his left front hoof after the race, but he recovered and went on to win the Haskell Invitational and Monmouth Stakes.

The Rick Dutrow-trained racehorse was never intended to race as a 4-year-old and was due to be retired at the end of the month after the Breeders Cup to stand at Three Chimney’s Stud in Kentucky.