On May 26, Bowie Race Track opened for its summer meeting under conditions that had not applied at a Maryland track in years: by orders of the state's racing commission, the horses were running without the benefit of drugs.

After two weeks, the suspicions of people who had criticized racing's "controlled medication" programs had been confirmed. The drugs Butazolidin and Lasix had been so potent that their use or nonuse could dramatically alter a horse's form. These drugs could have provided the means for some trainers to manipulate their horses' form and deceive the betting public.

Running at Bowie without drugs for the first time, odds-on favorites -- based on past performances with drugs -- suddenly were finishing well out of the money.

In those first two weeks of drug-free racing at Bowie, only 10 percent of the favored horses won -- compared with a national average of 33 percent.

Veteran handicappers suddenly found themselves confronted with a group of horses who, when forced to run without drugs, were different animals.

"Their form is definitely going to be different without drugs, but it will become more consistant as time goes on," said Bob Baker, a former owner and trainer turned antidrug crusader for the Humane Society.

"It will even out in the long run and you'll have a more honest game. You can manipulate the horses with drugs. If you have sore horse, you can run him without Bute (a painkilling drug) and build up his odds. Then you hit him with Bute and he really runs."

Baker, a former St. Louis stockbroker, spent two years researching and writing a book on drugs and horse racing after he left the racing industry in disgust in 1976.

"To a considerable extent," he wrote, "the drug abuse practice will invalidate many of the factors which formerly made betting attractive to the racing fan.Such things are speed ratings, track conditions, jockeys, weight, class and the like will have little relevance to the better who has to pick the winner of a race on the basis of which horse has the most stimulants or depressants in his system."

It was May 20 when the Maryland Thoroughbred Racing Commission, after months of racing controversy with the state's horsemen, adopted the National Association of State Racing Commissioners' recommendations on drug use. Those rules effectively ban the use of Butazolidin within 24 to 48 hours before a race, and sharply curtail the use of Lasix, a diuretic.

Legalized by most state racing commissions in the early 1970s, the use of Bute and Lasix have developed by the end of the decade into one of the fiercest controversies in the history of the sport.

Critics argued that Bute was being administered indiscriminately to sore and lame horses, permitting them to race when they should have been rested. Lasix, a treatment for horses who bled from the nostrils during or just after a race, also was said to mask the presence of other, illegal, drugs in postrace testing.

"Drugging makes the racing industry rife for a betting scandal that will drive the bettors away in search of a fairer product," aruged Rep. Bruce F. Vento (D-Minn), who introduced legislation last month to establish federal procedures for monitoring and controlling the use of drugs on racehorses.

"Trainers can use drugs to manipulate their animals' time(s) in the hopes of increasing the odds of them the next time they race . . . Unless there are substantive reforms, the future viability of racing will be in doubt."

Argues Tony Chamblin, executive director of the Horsemen's Benevolent and Protective Association: "We very much want to see the abuses corrected in areas where there are abuses. But we don't want to see the baby thrown out with the bathwater.

"They're talking about two very useful medications, namely Butazolidin and Lasix, and saying they are no good and are being abused. It is our opinion that they cannot be abused if a state enforces its rules and has modern testing equipment."

An all-out ban on Bute and Lasix, contends Chamblin, simply would encourage dishonest trainers to resort to a variety of illegal drugs.

"It's great to say that hay, oats and water are all a horse needs," Chamblin said. "But unfortunately in any phase of business there are a few people who will cheat, and horse racing is no different from any other sport.

"There are literally hundreds of drugs in the market that cannot be tested for. The cheater will be getting away with using something that can do great damage to a horse. The honest horseman who wants to abide by the rules will be victimized by the small group that doesn't."

Drug use long has been a volatile issue in the horse racing industry.

One of the earliest know efforts to control medication of racehorses occurred in 1966 when England announced a ban on all "exciting agents" in horse racing. In 1881, Prussia prohibited alcohol, which was said to make a cowardly horse courageous.

In the modern era, drugging resurfaced as an issue in the racing industry in the late 1920s and 1930s, and the drug heroin got its street name, "horse" from its early use at the track.

Probably the most celebrated instance of horse drugging occurred in 1968 when Dancer's Image was disqualified as winner of the Kentucky Derby after chemists found substantial amounts of Bute in his urine. (The drug subsequently was legalized in Kentucky and 22 other states.)

Over the years, numerous cases have been uncovered in which drugs were improperly administered to race horses.

In the 1970s, trainers and owners began pressing for legalization of Bute and Lasix, arguing that with the demands of year-round racing, Bute was necessary to keep the horses running. Most owners could not afford the expense of resting the horses, they claimed.

Lasix, they said, would be useful in the treatment of "bleeders" because it dilated a horse's blood vessels, reducing pressure on the walls of the vessels and reducing the chance of hemorrhage.

It quickly became apparent that the drug policies were being abused. Although no more than one in 20 horses is a bleeder, as many as 70 and 80 percent of those in a given race were being treated with Lasix.

Some horses ran all their races on Bute, while others received the drug in an off-again-on-again manner that altered their performances. For example Codex, winner of the Preakness, ran all of his races on Bute until the Belmont Stakes in New York, where the drug is illegal. There he finished a dismal seventh.

A filly named Veiled Look ran April 28 at Pimlico without Bute and finished last. On May 10, she ran at Pimlico with Bute and won by 12 lengths. A month later she ran at Bowie -- a big favorite at 3 to 10 -- without Bute and finished out of the money.

It is a fact of life in the racing business that many trainers and owners feel they must try to deceive other horsemen about an animals's ability, and the legalized drugs offered a prime opportunity to do just that.

Most races are claiming races, run under conditions that permit other horsemen to claim any horse in the field for a predetermined amount of money until 15 minutes before the race. If a horse is good and has a chance to win, it may be in an owner's interests to have had him run poorly previously to discourage potential claimers.

Furthermore, it costs about $15,000 a year to keep a horse, while the average thoroughbred's winnings are only $8,000. Some horsemen try to make up the difference at the betting windows. Any way the odds can be manipulated for a maximum payoff is, of course, helpful.

In addition to Maryland's ban on drugs, racing commissions in Pennsylvania, Illinois, California, Florida, Ohio, Kentucky and Colorado either have banned or have taken steps toward banning Bute and Lasix, according to the National Association of State Racing Commissioners.

Vento, however, says a state-by-state approach won't do.

"The insterstate nature of racing makes a state-by-state approach impossible," he claimed. "Only a federal program can successfully control the abuses associated with drugging."

Vento's bill -- which contends that drugging corrupts horse racing's integrity, misleads the betting public and creates an unreasonable risk of injury or death to horse and rider -- would provide for prerace testing of all horses in a race.

Most tracks now test only the first two finishers or, in the case of a trifecta, the first three. That practice has been described as inadequate by critics of the industry.

"If you're going to fix a race, it's easier to drug a horse to lose, because they only test the winners," said Marc Paulhus, an investigator into drugs and horse racing for the Humane Society.

Additionally, Paulhus argues, "There are more drugs that they can't find than there are that they can find. There are at least 30,000 different compounds that can be used on a horse. Not only is it harmful to the animal, it's a consumer ripoff and it's dangerous to the jockey."

Moreover, Paulhus contended, drugs abuse interferes with breeding.

"We're breeding a drug-dependent horse, an inferior horse," he said.

In the meantime, at the close of each day's racing at Bowie, a courier picks up blood and urine samples from the winning horses. Sealed in pint-sized mason jars, the samples are driven to a laboratory in a basement at Laurel Race Course, where Maryland's racing chemist, Thomas F. Lomangino, analyses them for drugs or foreign substances.

In recent years, Lomangino said, the scope and sophistication of his operation have increased significantly and the state has spent thousands of dollars on new equipment.

But he added, "If a guy down the street is putting a new drug on the market, how do you expect us to find it?"