SARATOGA SPRINGS, N.Y. -- When Lady's Secret became the top money-winning mare of all time by capturing a minor race last month, the occasion appeared to be the optimal moment to retire her.

The champion was clearly past her prime; she couldn't beat top competition anymore. She could have gone out in glory, with appropriate ceremonies and fanfare, maybe a nice "Lady's Secret Day."

However, that is not the style of trainer Wayne Lukas, who typically keeps his horses running until they become too infirm to run anymore.

So, instead of ending in triumph, the illustrious career of Lady's Secret probably ended in ignominy, on a gloomy, muddy day at Saratoga. It happened Monday afternoon when jockey Chris McCarron pulled her up on the backstretch because Lady's Secret was unable or unwilling to finish a minor allowance race.

Instead of getting the cheers befitting a champion, she walked off a race track for what might be the last time to a few scattered boos and a few curses at McCarron, but mostly stunned silence.

Even though her recent races had borne no resemblance to the form that made her 1986 horse of the year, Lady's Secret still was the 1-to-5 favorite. But as soon as the gate opened, she attempted to bolt toward the outside fence. McCarron had trouble controlling her, finally stopping the gray mare by the fence on the backstretch.

"I don't know what happened," he said. "I don't know what's wrong with her. She acted like she wanted to go back to the barn instead of being out on the race track. It appears that she's disinterested in racing. She just wouldn't cooperate."

What's wrong with Lady's Secret has been no mystery to most people in racing. After competing steadily for almost two years without a real vacation, after winning more Grade I stakes than any horse has ever won in a single season, after earning some $3 million, Lady's Secret was worn out, mentally and physically. She showed no zest for training earlier this year, and she lost her first start of 1987 by 32 lengths. When she returned to action after a short rest, she won a couple of easy allowance races but she wasn't the old Lady's Secret.

But neither Wayne Lukas nor his son, Jeff, who has been in charge of Lady's Secret here, would face reality. Just a few days ago, Jeff Lukas was asked about opinions that the mare had lost her old zip and he shot back, "That's bull. The only people who have retired her are the so-called experts in the press."

As Wayne Lukas' stable has become the biggest, richest and most powerful in America, his ego has seemingly grown in proportion. He acts as if he expects his horses to respond to his sheer will, as if the ordinary precepts of training mean nothing to him. If anyone criticizes his wisdom, Lukas will tell them that they are morons, or worse. When he is proven wrong, and he winds up ruining a horse, he will never admit it. The horse will just quietly disappear from view. People at Saratoga Monday were reminded of this after the Lady's Secret debacle, when Capote made his return to competition.

The 2-year-old champion of last season, Capote finished out of the money in his first two starts this year, but Lukas ignored the evidence and the horse's poor form and took him to the Kentucky Derby anyway. When even friendly reporters questioned his judgment, Lukas responded with nasty epithets. Yet when Capote was eased and failed to finish, Lukas never acknowledged he might have made a mistake.

There is no surer way to ruin a horse than to push him to run in races for which he is ill-prepared. Horses can't withstand this kind of mistreatment. When Capote made his first appearance since the Derby in an allowance race Monday, he raced head-and-head for a half with a moderate allowance horse named Quick Call -- and was run into the ground. Capote faded and was beaten by nearly seven lengths. He may be a semi-productive race horse, but he'll certainly never be a star again.

Lady's Secret won't even be semi-productive. She's finished. In keeping with Lukas' tradition, Jeff wouldn't acknowledge reality. Asked if this were the end of the line for Lady's Secret, he responded, "It would be premature to say. Those decisions will have to be made later."

Actually, the decision should have been made months ago. The Lukases were virtually the only people in racing who didn't recognize it, or didn't think that Lady's Secret deserved to bow out in a fashion befitting a champion.