Owner Paul Barber has revealed Cheltenham Gold Cup hero Denman has spent the last five months in a veterinary hospital fighting for his life after contracting a potentially fatal infection.
The Paul Nicholls-trained gelding beat stable companion Kauto Star in one of the most highly anticipated Cheltenham Gold Cups in history in 2008 and was then runner-up to his great rival 12 months later.
He was also second in the following two runnings of the blue riband event before being retired late in 2011 after suffering a tendon injury.
The 13-year-old had been enjoying his retirement at Charlotte Alexander's yard near Cheltenham, where he has been a team chaser and hunter, until being struck down by illness earlier this year.
While Barber admitted it was "touch and go" for the horse affectionately known as "Tank" during his racing days, he now hopes his pride and joy is over the worst.
Barber said: "He's got a horrible piece of swelling round his back fetlock joint, which is going down every week. I can only pray and hope that he'll make a full recovery."