By Pete Denk and Frank Angst

After winning the Kentucky Derby presented by Yum! Brands (G1), Barbaro broke down in the Preakness Stakes (G1), which started an intensive effort to try to save his life. A timeline of Barbaro’s battle to recover follows.

May 20
Barbaro suffers fractures to the sesamoid, pastern, and cannon bones in his right hind leg shortly after the start of the Preakness Stakes (G1). He is transported to the University of Pennsylvania's New Bolton Center, where he arrives at about 9 p.m.

May 21
Dean Richardson, D.V.M., operates on Barbaro for more than five hours, inserting 27 screws, a titanium locking compression plate, and a bone graft into the shattered leg. Barbaro emerges from the surgery well, jumping when returned to his feet and pulling his handler while trying to gallop back to his stall.

May 22
Barbaro shows a strong appetite and nickers at any nearby mares. Vital signs are good.

May 30
Jockey Edgar Prado visits Barbaro, who had an “incredibly good week,” according to Richardson. Prado reports Barbaro looks bright and healthy.

June 8
Pennsylvania Governor Ed Rendell visits Barbaro and presents the New Bolton Center with a $13.5-million check earmarked for the Barbaro Fund. Barbaro is reportedly frisky and doing extremely well.

June 13
Richardson puts Barbaro under general anesthesia and replaces the cast on his right hind leg for the first time. Richardson reports the incision is healing well, the graft is taking, and the screws and plate appear unchanged.

July 1
Barbaro shows a slightly elevated body temperature and appears uncomfortable in his hind legs.

July 3
Richardson puts Barbaro under general anesthesia to reassess the leg and replace the cast. Richardson also replaces two bent screws and adds three new ones to the pastern joint.

July 5
Barbaro is not comfortable with his new cast and it is replaced again. Doctors discover a small infection on Barbaro's left hind foot, near the frog. Barbaro receives topical antibiotics and a new protective shoe.

July 8
Barbaro's right hind leg shows signs of infection. Richardson replaces the plate and many of the screws in Barbaro's leg and adds a fresh bone graft while cleaning the site of the infection. It takes Barbaro longer to recover from the anesthesia than in the past. Barbaro also receives a new long cast along with pain medication and antibiotics.

July 10
Richardson places Barbaro under mild sedation to replace the long cast with a shorter one. Barbaro's temperature and heart rate return to normal.

July 11
Doctors change the bandage on Barbaro's left hind foot, where the abscess is located. Barbaro shows signs of laminitis in the left hind foot late July 11 or early July 12.

July 12
Richardson reports Barbaro is facing tough odds and describes his condition as guarded. Richardson said he is focusing on diagnostics and keeping Barbaro comfortable. He stays in constant consultation with breeder/owners Roy and Gretchen Jackson.

July 13
Richardson says Barbaro has acute laminitis in his left hind foot. He says the laminitis is, “as bad as it can be” and describes Barbaro's chance of survival as “poor.” Barbaro is under intensive pain medication and is allowed to rest in a sling for about 12 hours.

July 14
Richardson reports Barbaro had a restful night, sleeping on his side for four hours. The colt's condition is described as stable, but extremely serious.

August 16
Barbaro recovers to the point that he begins going outside to graze on grass. He no longer spends time in a sling to keep weight off his hind legs.

November 2
Trainer Michael Matz and his assistant Peter Brette pay regular visits to Barbaro, who settles into a steady routine in his recovery. Barbaro goes on daily walks with Brette.

December 19
Equine hoof specialist Scott Morrison D.V.M. examines Barbaro’s left hind foot. Morrison performs some work on the hoof and offers some recommendations.

January 9
Barbaro shows acute discomfort in his left hind foot and vets discover a portion of the hoof wall had separated from his laminitic left hind foot.

January 13
Under general anesthesia, additional hoof wall is removed from the left foot and a tendon in Barbaro’s left hind leg is cut to relieve tension from the coffin bone. A cast is placed on Barbaro’s right hind leg for additional support.

January 19
Barbaro’s attempt to recover is voted the National Thoroughbred Racing Association’s Moment of the Year.

January 22
Team Barbaro receives a Special Eclipse Award for their efforts to help the Derby winner recover.

January 24
Barbaro is placed under anesthesia and the cast on his left hind foot is replaced. The cast on his right hind leg is replaced with a custom-fabricated plastic and steel orthotic brace to give his foot additional support.

January 27
After developing a deep subsolar abscess while going through a period of discomfort in his left hind foot, surgery is performed on Barbaro to put in place an external skeletal fixation device to provide the foot a chance to heal.

January 28
Unable to lie down, and with both front feet showing negative signs, Barbaro is euthanized.

Pete Denk is a Thoroughbred Times staff writer

Frank Angst is a Thoroughbred Times senior staff writer