Fans are sending flowers, cards and carrots to the hospital where Barbaro is recovering.
The Kentucky Derby winner broke three bones in his leg at the Preakness in Baltimore Saturday.
A doctor who performed surgery on Barbaro for five hours yesterday says the horse's survival is "a coin toss."
The operation was to repair rear leg bones Barbaro broke Saturday in the Preakness, with his chances at survival listed at 50-50.
They say the horse calmly woke up from anesthesia and "practically jogged back to his stall" for food.
Richardson had stressed before the marathon operation that he's never worked on so many catastrophic injuries to one horse.
He said after the surgery that Barbaro "is extremely comfortable in the leg."
Barbaro broke down only a few hundred yards into the one and three-sixteenth-mile Preakness, two weeks after winning the Kentucky Derby.
Barbaro had been unbeaten until yesterday.