Seventeen years after Lasix was introduced to American tracks, the racing industry still can't agree whether the medication should be legal for treating horses who bleed.

Those who oppose Lasix say it is wrong to race horses dependent on a drug -- especially when that drug may enhance their performance, as Lasix evidently does. Those who favor Lasix point out that modern thoroughbreds suffer from internal bleeding in almost epidemic numbers, and argue it is senseless and inhumane to deny them help for this common condition.

Both arguments are right. That's why the sides are so hopelessly polarized, and no compromise seems possible. Yet even though the Lasix controversy seems insoluble, a scientist in Silver Spring says he sees the way to resolve it.

John H. Boucher holds a doctorate in physiology. He was a U.S. Army veterinarian for many years. One of his main interests as a researcher has been hemorheology -- the mechanics of blood flow -- and he formed his company, Rheotech Labs, to study blood flow as it affects horses.

In Boucher's view, the raging debate over Lasix has missed what should be the central point. The racing industry has been preoccupied with the treatment for bleeding but hasn't dealt with the question of what makes horses bleed.

There is no known cause for the malady that is known as Exercise Induced Pulmonary Hemorhage, or EIPH. The problem has existed as long as the thoroughbred species has existed, but it is only in recent years that modern diagnostic techniques have shown veterinarians and trainers that the majority of horses experience EIPH. If the cause is surrounded by mystery, so is the treatment. Experts can't explain why Lasix helps the condition; the recent University of Pennyslvania study says that Lasix in fact doesn't stop bleeding.

Boucher became interested in this issue in 1978 when, as part of a project for the Armed Forces Institute of Pathology, he studied horses who took part in an endurance ride in Virginia.

In the hardest portion of the ride," he said, "we discovered abnormal red blood cells in the horses. For the past 10 years I have been researching what those cells are."

Boucher's conclusion, in short, is this: When horses exercise vigorously, they produce abnormal red blood cells called echinocytes. Seen under a microscope, they are irregularly shaped, as opposed to the disklike shape of a normal cell. These echinocytes are rigid cells that tend to clump together, impeding the normal flow of blood. This congestion causes pressure to build up in the blood vessels of the lungs and, as a result, the horse bleeds.

And Boucher thinks pulmonary bleeding is only one of the bad effects caused by this poor blood flow. Thoroughbred horses are the most fragile of athletes. In a sport that involves no physical contact -- only running -- the attrition rate is so high that most owners can never make money. A sizable percentage of horses that start training never get to the races at all because of injuries.

"I believe," Boucher said, "that the quality of blood flow to tissues of exercising horses is important -- if not the key -- to exertional diseases."

If these echinocytes are indeed the cause for so many equine problems, what is the remedy? There are already drugs, described as "hemorheological," which have been proved effective in restoring blood flow in humans. (Echinocytes aren't as serious a problem for humans, but they are observed routinely in various conditions and activities.)

Boucher proposes to experiment with and develop drugs specifically for use on horses. He says that such medications would be otherwise innocuous. They would fit the sport's definitions of legal medications, and they presumably wouldn't affect horses' performances.

Now Boucher is trying to find the funding for his research project, and he has showered racing commissions and other organizations with letters, press releases and publicity packets. How much response has he received for an idea that addresses one of the most troublesome issues in the industry?

"None," he said. "I've gotten ignored -- but it's nothing that unusual. People have no way of knowing if you know what you're talking about." He points out that his ideas are built on a new science, hemorheology, that isn't even in the curriculum of veterinary colleges. Boucher says he is the only veterinarian who is a member of the International Society of Biorheology.

As a former B student in high school biology and chemistry, I would not presume even to guess whether Boucher knows what he's talking about. But he certainly makes as much sense as the people with rigid pro-Lasix or anti-Lasix positions.

And his basic approach makes sense, too: Find out what causes horses to bleed from the lungs, and find a drug to treat it that has none of the negative or controversial aspects of Lasix.