When Timely Writer was forced to withdraw from the Jerome Handicap because of the results of a prerace drug test, his veterinarian denounced the decision as "an absolute outrage." His trainer and owner were stunned by the capricious rules that may cost them the horse of the year title. Racing fans who had gone to Belmont Park to watch the country's preeminent 3-year-old went home disappointed.

But while nobody was happy about Monday's events, they demonstrated the virtues and effectiveness of a drug-testing program that is unique in the thoroughbred industry.

The sport traditionally has relied on postrace tests to detect horses who have been illegally medicated. New York wanted to head off some these scandals before they occurred, and instituted prerace blood tests more than a year ago.

"Ninety-five percent of what used to constitute postrace positives can be found on the prerace test," said John Dailey, director of planning and policy for the New York State Racing and Wagering Board. In the morning, three state veterinarians take blood samples from horses who are to race that day, and send those samples to a state lab for analysis. If one shows positive for a prohibited drug, the horse is retested. Then the findings are reported to the stewards, who will order the horse scratched if there is a second positive.

One of the difficulties under this or any other drug-testing system is that a horse may be treated with certain medications -- antibiotics, for example -- but may not race with them in its system. So that such medications won't show up in a test, New York forbids the administration of some antibiotics within 48 hours of a race. But if a horse's metabolism works slowly, the drug might show up anyway. This is apparently what happened to Timely Writer.

The colt had a cough last week and William O. Reed, his veterinarian, said he gave Timely Writer a shot of Albon, a sulfa drug, Friday morning -- about 80 hours before the Jerome Handicap. But a drug enforcement system can't rely on the assurances of the vets (who may be, after all, the rule breakers that the tests are supposed to catch). So when Timely Writer's blood test was positive for sulfadimethoxide, he had to be scratched.

While this was bad luck for the horse, the prerace blood tests nevertheless eliminate more problems than they cause.

"Initially," Dailey said, "the horsemen thought this was going to cause them trouble. They learned that while the program is designed to protect the public, it primarily protects trainers by screening out horses that would cause them to go down (be suspended) for 30 or 60 days. By and large, they have welcomed the testing with open arms."

A trainer whose horse flunks a postrace test faces a suspension or a protracted legal battle. A prerace positive is quickly forgotten. Last year a filly named Banner Gala had been given an illegal drug before a major stakes race; this was something of an embarrassment because she was owned by Ogden Phipps, chairman of the Jockey Club. But because the drug was detected in a prerace test, there was no scandal; Banner Gala was scratched, trainer Angel Penna made some excuses and the incident quickly was forgotten.

Trainer Dominic Imprescia, who has been suspended for serious drug violations in the past, will be spared the problems that might have arisen from a postrace "positive" on Timely Writer. But, of course, the scratching of the horse gives him other problems.

The Jerome Handicap was a crucial part of the colt's comeback schedule; he needed that one-mile race as a prep for Sept. 18's 1 1/4-mile Marlboro Cup. Now, Imprescia says, he will try to bring Timely Writer into the race on workouts, but the colt will be operating at a considerable disadvantage.

After having been knocked out of the spring Triple Crown races by an illness, Timely Writer's chances of winning Belmont's fall championship races now look bleak, too.

The cause was neither wrongdoing on the part of his trainer or veterinarian, nor any unfairness inherent in the testing system. It was plain bad luck.