Racing:Fondmort is fighting for his life in a veterinary hospital with internal bleeding after fracturing his pelvis.
The popular 10-year-old chaser is in the RVG Valley Equine Hospital in Lambourn after sustaining the injury in his final piece of work before the Paddy Power Gold Cup at Cheltenham on Saturday.
The gelding's trainer Nicky Henderson reports the next 24 hours to be vitally important.
"He's critically ill. He's fractured his pelvis but that has caused some serious internal bleeding which has haemorrhaged," said Henderson.
"We managed to get him from the gallops where he was doing his last bit of work before the Paddy Power this morning.
"He was doing the same thing he has done so many times before and Vicky Pearce, who has looked after him all of his life, was riding him. He's in the hospital and he's on a transfusion and is having massive pain relief.
"The reason he is going quite stable at the moment is because they say the horse's temperament is just so amazing that he has coped with the trauma that has happened.
"It's the internal bleeding that is the danger and the next 24 hours are absolutely critical.
"This is desperate for his owners Bill and Tracy Brown and for everybody. He's never missed a day's work in his life. It's going to be fingers crossed."
Fondmort was due to carry top weight of 11st 12lb in the Paddy Power at Cheltenham where he has recorded four of his nine career wins - including this race in 2003.