Until recently, Barbaro--the majestic 3-year-old Thoroughbred who stormed to victory in the Kentucky Derby in May--seemed to be recovering nicely after sustaining a severe break in his right leg during the May 20 Preakness Stakes. But after surgery on July 8 to replace hardware and clear up an infection in that leg, doctors found and treated an abscess in his previously healthy left foot. But the inflammation worsened: Barbaro had developed laminitis, a breakdown of the tissue joining his foot bone and hoof.
Laminitis, which is caused by favoring an injured leg and putting too much weight on the healthy...