The Willie Mullins-trained Ballyward had to be put down after falling in the National Hunt Chase at Cheltenham on Tuesday.
The 9-4 favourite fell at the 17th fence of the four-mile marathon and sustained fatal injuries.
“Our vet team very sadly determined it was necessary to euthanise on welfare grounds,” a racecourse statement outlined. “As animal lovers we hate to lose any horse and of course we shall review this incident.”
There is extra focus on animal welfare this week on the back of last year’s festival when six horses sustained fatal injuries.
Ballyward’s sad fate was part of a mixed day for Mullins who won the first two Grade races but later saw the odds-on Benie Des Dieux fall at the last in the OLBG Mares’ Hurdle when looking a likely winner.
Benie Des Dieux was reported to be unharmed after her exit.
Irish jockey Finny Maguire was taken to Southmead Hospital in Bristol for further assessment after falling from Whisperinthebreeze at the 14th fence of the National Hunt Chase.
Just four of the 18 runners finished the race. Eight horses fell in total, one rider was unseated while five runners were pulled up.
