Since Barbaro underwent emergency surgery to treat a leg injury the horse suffered in the Preakness on May 20, Richardson, the chief of surgery at the University of Pennsylvania's New Bolton Center, guarded any cautious optimism with the reality of the situation, saying Barbaro had a 50-50 chance of survival despite any progress the horse had been making, according to USA Today.
"It could happen within 24 hours," Richardson said during a news conference at the University of Pennsylvania's New Bolton Center.
Richardson said Barbaro has a severe case of laminitis in his left hind leg - a painful, often fatal disease caused by uneven weight distribution in the limbs.
Richardson, who has treated Barbaro since the colt suffered catastrophic injuries in the Preakness on May 20, said 80 percent of the horse's left hoof wall was removed Wednesday with the sudden onset of the disease.
Though he looks just fine, that doesn't reflect the true nature of his condition, termed "poor" by Richardson.
Until his misstep at the Preakness, Barbaro's career was nothing short of brilliant.
He won his first five starts, including the Florida Derby. His 6 1-2-length victory at the Derby was so convincing he was being hailed as the next likely Triple Crown champion - and first since Affirmed since 1978.
But seconds after the gates swung open at Pimlico, that career was cut short when the colt broke down, his right hind leg flaring out awkwardly because of three broken bones.
Race fans at Pimlico wept and within 24 hours the entire nation seemed to be caught up in a "Barbaro watch," waiting for any news of his surgery and condition.
And for the longest time, it all seemed to be going well.
Barbaro's first six weeks of recovery were relatively smooth - despite five hours of surgery to insert a titanium plate and 27 screws into his three shattered bones.
Each day brought more optimism: Barbaro was eyeing the mares, nickering, gobbling up his feed and trying to walk out of his stall. There was great hope Barbaro somehow would overcome the odds and live a life of leisure on the farm, although he'd always have a hitch in his gait.
Richardson, along with owners Gretchen and Roy Jackson and trainer Michael Matz, all believed the colt had a chance to recover.
Until last week, when Barbaro's condition steadily worsened.
The colt underwent three surgical procedures and four cast changes on the injured leg, followed by a hoof wall re-section to remove 80 percent of his left rear hoof, according to the AP.
Within hours of the grim update, roses and apples began arriving at the hospital, and hundreds of get-well e-mail messages were posted on a Web site set up by the New Bolton Center.
KGB General Nikolai Leonov, who personally knew Lee Harvey Oswald, talks about the version of John F. Kennedy's assassination on the orders from Nikita Khrushchev