Big Brown, the horse with a chance to be the first Triple Crown winner in 30 years, was back on the track galloping yesterday morning at Belmont Park. For the next 10 days, all interested eyes will remain on Big Brown's left front hoof, the one that developed a quarter crack after the Preakness Stakes.

Big Brown's trainer, Rick Dutrow, and the foot specialist in charge of his care, Ian McKinlay, both expressed confidence yesterday that the three-quarter-inch crack had not turned into a performance-altering problem. The crack is in the quarter, an inside portion of the hoof. There were no signs of infection, they said.

However, Big Brown's history of foot problems has everyone watching closely. The horse was out of training for a month after a larger crack was discovered in the left front hoof in December. That time it became infected.

Trainers, blacksmiths and other experts say that if Big Brown's problem is as minor as is being reported, the Kentucky Derby and Preakness winner should have no problem being ready for the June 7 Belmont Stakes.

"They've gotten so sophisticated now to correct these things with wire," trainer Michael Matz said yesterday at Delaware Park. "I don't know the type of quarter crack it is. But if it's the type of thing that can be handled, it's usually a couple of days and they're back going."

Cracks can be caused by a number of factors, including concussion with hard surfaces, thin hoof walls, and foot imbalance. It is not known what factors contributed to Big Brown's latest crack, although McKinlay, a second-generation equine foot specialist, has talked about more horses developing wall cracks from the hard Belmont surface over the last year.

This week, Big Brown's quarter crack was reportedly cleaned up and treated with drying agents, then laced with sutures, to stabilize the crack.

"Stitching wasn't [widespread] 20 years ago," said Philadelphia Park-based blacksmith Dean Musser, who has worked on horses' shoes for 33 years. "It's like a shoelace, basically."

The next step is to patch over the crack with fiberglass.

"It actually fills it up better than his regular hoof," said trainer Lou Albertrani, who also was at Delaware Park yesterday. "It's real strong."

The issue isn't whether Big Brown could develop a problem that could cause him further harm, Musser said.

"It's not like an ankle problem," Musser said. "It wouldn't break him down. But it wouldn't let him run to his full potential."

Big Brown first suffered a quarter crack and hoof separation on his inner right front hoof last fall, then suffered a similar injury in December to his inner left front hoof. The horse did not race between his debut Sept. 3 and March 5. He became the first Kentucky Derby winner to win with glue-on shoes, designed by McKinlay. The shoe features a rubber composite that provides additional cushion.

Albertrani said he is a believer in glue-on shoes. McKinlay suggested that Albertrani's sprinter Artax use a variation of them for the 1999 Breeders' Cup because the colt had bruised feet. Artax won the Breeders' Cup Sprint that year. Albertrani said he took "a big chance" because the horse had never run on them before and he did not know how Artax would perform.

Big Brown has been using those shoes all year. Before the Derby, his caretakers talked about his foot problems being a thing of the past.

"This could be something that is part of him," Musser said of the quarter crack. "Once they have them, they tend to come back."