A year later, the questions about his most famous client keep coming.

Last week, Dean Richardson stood in a high school auditorium and answered them, for nearly two hours. He talked about how Barbaro's specific injury does not occur in any other animal but a racehorse, how waking horses from surgery is always a tricky business, because "a horse is an animal that is afraid of being eaten . . . they try to get up and run away."

The chief of surgery at the University of Pennsylvania's New Bolton Center showed a photograph of how laminitis ravaged Barbaro's left hind foot and radiographs of what it looked like inside the foot. He sometimes talked clinically, but mostly for the layman, about the 2006 Kentucky Derby winner's undoing.

At the end, Richardson said, "I'm recognizing that we didn't succeed. I'm half-embarrassed to be here - to present my failure."

However, he is not embarrassed, Richardson said, by any of the treatments used to attempt to save Barbaro's life. He might tweak things, he said, but doesn't know that any of it would have changed the course of events.

He acknowledges that all sorts of issues came to the forefront because of Barbaro - certainly, awareness of laminitis and the need for more research into the disease that was primarily responsible for Barbaro's demise.

All the attention focused on New Bolton during Barbaro's stay never unnerved him, Richardson said.

"The actual emotional toll of it - 90-plus percent of the time, I did not have that much trouble dealing with it," Richardson said in an interview. "At times, it was overwhelming, but not because of the pressures from the public. But just because you felt like you were letting the horse down. The horse was my patient. The American public was not my client."

Richardson's talk included a video that showed Barbaro winning the Derby - "the honest truth, I cannot watch that to this day without getting goose bumps," Richardson told the audience.

But when video of Barbaro breaking down in last year's Preakness appeared, Richardson turned away and took a swig from a bottle of water, and then another swig, and he kept his eyes averted from the screen, never changing expression.

"I don't watch that," Richardson said the next day. "I don't want to watch. That's the only thing I really have difficulty watching."

The man in charge of Barbaro's care for eight months wants it understood that he is not continually reliving the last days of Barbaro's life before the horse was put down on Jan. 29.

"Nope, nope," Richardson said in the interview. "I certainly can get choked up. But I have a lot of work to do. I have to move on. I don't want that overblown by any means. I've got to be a grownup and move on. . . . It is what it is. You go on."

But Richardson, one of just a handful of surgeons equipped to handle Barbaro's catastrophic injuries, also wants this understood: He has looked back to second-guess everything.

"If you're not, what good are you?" Richardson said. "That's like implying that everything is due to fate, and to God's will. . . . In this type of clinical work, you look at everything, asking, 'Would the outcome possibly be different?' If you don't ask the question, you can't even know conceivably know the answer. Just thinking about the question leads you to a better place."

He's wondered about what would have happened if he had done the original surgery slightly differently last May, but has no idea whether it would have made a difference, or exposed the horse to a greater risk of infection.

"He tried as hard as he possibly could," Barbaro's trainer, Michael Matz, said of Richardson. "I think it's a little unfair to say some things. It's like anything else. It's always easy to say afterwards. When it doesn't work out, it's only human nature to look at things. In the next case, I think Dean will probably change some things."

Richardson said he has spoken to Matz several times since Barbaro was put down and hoped that if Matz had another horse in need of surgery, "he would still call me up. I'd be surprised if he didn't."

Matz said he wouldn't hesitate to go to Richardson again with one of his horses.

"Oh, yes," he said.

Not that any horse owner or trainer always wants to be in his presence, Richardson said.

"I'm like your dentist," Richardson said. "You don't necessarily want to see me."

The fee for Richardson's talk, given at Hatboro-Horsham High and paid by the Hatboro-Horsham Education Foundation, went toward laminitis research. It was his hope, Richardson told the crowd, that a difference could be made in five to 10 years.

Others issues also got attention, some involving racetrack safety. Richardson said much scientific work has to be done to determine whether the artificial surfaces being installed at many racetracks turn out to be safer.

"I do believe - I personally believe - that the Triple Crown could be made a little bit better by stretching it out," said Richardson, although he said of Barbaro, who never lost a race he finished: "He was a dead-sound horse."

After Barbaro was put down, Barbaro's owners, Roy and Gretchen Jackson, donated $3 million to Penn's veterinary school, endowing a chair in Richardson's name. In addition, more than $1.7 million has been donated from the public, much of it earmarked to study laminitis.

Richardson has gotten "extraordinary" support from the public, he said, with a tidal wave of letters coming in after Barbaro was put down. But he's also gotten some hate mail. He saved one recent voice mail from a woman who called Roy and Gretchen Jackson "wonderful people" and then - "here's my favorite part," Richardson said - she called him two obscenities and said she "prays to God that horrible things happen to you" and that he loses his license and that Barbaro sees him in heaven to pay him back.

Richardson called the voice mail "not even remotely upsetting - I guess it proves that you can't exactly get through to all the people."

All along the way, people contacted him with advice.

"Scores of people sent me pictures and drawings of their dogs in that little wheel thing," said Richardson, who was already familiar with the device. "I had a Welsh Corgi for a year in that little cart."

His short answer of why that wouldn't have worked, and why Barbaro couldn't have just stayed more in a sling throughout his recovery: "Horses do not thrive if they can't stand on four legs." He mentioned many possible complications, but offered hope that "somewhere down the road" somebody invents a device that suspends a horse's weight without side effects.

For Richardson, the last year obviously has been a blur. His research lab "was neglected to a considerable extent," Richardson said, and he didn't get to the scholarly writing he typically would in a year. He wasn't complaining, just saying it matter-of-factly.

When he talks, Richardson always tries to make the point that the vast majority of Barbaro's days were good ones. He doesn't deny that he got extremely close to this patient. His best memories, he said, are of being alone with him as Barbaro grazed.

"It's like people. Some are nice, but kind of dull," Richardson said. "Others are just mean as snakes. . . . Barbaro, he was always interacting with his surroundings."

Barbaro's surgeon added, "He seemed a little larger than life, because he did some larger-than-life things."

Contact staff writer Mike Jensen

at 215-854-4489

or mjensen@phillynews.com.