The 4-year-old horse will be supported by a sling for several hours each day after the removal of damaged tissue in his hoof, according to a statement from the University of Pennsylvania's George D. Widener Hospital. X-rays taken yesterday showed no additional complications in either hind leg.

"He is getting up and down on his own and continues to eat and have stable vital signs," Dean Richardson, the horse's chief surgeon, said. "We are considering several additional therapeutic options at this time."

The surgery was performed on the hoof that developed an inflammation known as laminitis as Barbaro recovered from an operation on his right rear leg, which was broken during the Preakness Stakes on May 20. He had 80 percent of his hoof wall removed in July.