May 20: Three bones in his right hind leg shatter at the start of the Preakness Stakes. Jockey Edgar Prado dismounts immediately.

May 21: Barbaro undergoes a five-hour operation at New Bolton Centre in Pennsylvania, during which 27 screws and a titanium plate are fitted. His surgeon, Dean Richardson, says the horse's future is uncertain.

May 22: Barbaro begins life in the centre's intensive care unit, his leg encased in a fibreglass cast from hock to hoof.

May 27: A special shoe is fitted to his other hind leg to reduce the chance of it developing laminitis due to it taking too much weight.

May 30: Jockey Edgar Prado pays Barbaro a visit.

June 13: Cast is changed for the first time. Surgeon Richardson is pleased with how the leg is looking.

June 18: Progress is said to be pleasing.

July 5: Discomfort persuades surgeons to replace the cast. A small abscess is treated on the sole of his uninjured hind hoof.

July 8: More surgery to treat infection in leg; A new cast is fitted, providing even more support. The plate and some of the screws are replaced. Two days later a new cast is fitted.

July 13: Barbaro has laminitis in his uninjured rear hoof, Richardson reveals. Eighty percent of the hoof is removed in a bid to keep the problem under control. Richardson says the horse's prospects are "poor".

July 14: Barbaro is doing as well as can be hoped. The aggressive treatment of the laminitis appears to be working, but surgeon Richardson warns a few days later that recovery will be a long haul.

Aug 9: Condition has continued to improve. Barbaro begins outings to a grassy areas next to the intensive care unit to to the unit to eat grass and enjoy the outdoors.

Aug 17: The supportive sling is removed and he is taken off painkillers.

Sept. 26: The right hind leg is progressing well and the removed hoof on the other hind foot is beginning to grow back.

Nov. 6: Barbaro has the cast taken off his lower right hind leg.

Dec. 13: There is talk from Richardson of Barbaro leaving the animal hospital in the near future.

Jan. 2, 2007: Richardson talks of the leg getting stronger and believes Barbaro can live a comfortable life.

Jan. 10: A major setback is reported. Damaged tissue is removed from Barbaro's left hind hoof, a week after a new cast was put on Barbaro's laminitic left hind foot. The cast was designed to realign the bones.

Jan. 13: More left hind hoof is removed. A cast is refitted to his right hind leg to give support.

Jan. 24: A new cast is put on his laminitic hoof, and a plastic and steel brace is put on his right hind leg.

Jan. 27: More surgery. Two steel pins are inserted in a bone to eliminate all weight bearing on the ailing right rear foot. A new external brace is fitted.

Jan. 29: Barbaro is euthanised. Co-owner Roy Jackson reportedly said: "We just reached a point where it was going to be difficult for him to go on without pain."