Big Zeb, winner of the Queen Mother Champion Chase at Cheltenham in 2010, has been retired.
Trainer Colm Murphy took the decision to call time on the 12-year-old's highly successful racing career due to problems with the horse's joints.
Big Zeb has not responded well enough to treatment after he finished fourth to Sizing Europe in the Dial-A-Bet Chase at Leopardstown over Christmas.
"It's a pity, but unfortunately he's had a few niggly problems," said the County Wexford handler.
"He didn't come out of Leopardstown as well as we'd hoped.
"His joints are troubling him a little bit. He deserves his retirement now.
"The decision was made for us. We gave him a bit of time, but he still hadn't responded to treatment so we are retiring him for his own sake.
"He has been so good to us so it's the right thing to do.
"Winning the Champion Chase at Cheltenham would have to be the highlight.
"He's been good and Leopardstown was lucky for him as well.
"We had many good days but the Queen Mother was the icing on the cake.
"I imagine he'd go home to his owner Pat Redmond. He has his own place not too far from here near Gorey."
Big Zeb won 13 of his 33 starts and amassed over £813,000 in prize-money.
His victories included three wins in the Dial-A-Bet Chase and the Boylesports.com Champion Chase at Punchestown in May 2011.
He was also placed in the last two runnings of the Champion Chase at Cheltenham.