02/14/2003 12:00AM

Taking a new look at an old drug

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Six recent positive test results for the anti-inflammatory medication dimethyl sulfoxide at Gulfstream Park are raising concerns that the mild, widely used medication is being administered in new, unorthodox ways to kill pain or prevent fatigue in racehorses.

According to Gulfstream stewards, the trainers whose horses tested positive for dimethyl sulfoxide, or DMSO, were Barbara Pirie, Steve Asmussen, Mike Gorham, Victor Falzone, Allan Hunter, and Rodolfo Garcia. Each trainer was fined $100, the stewards said. The stewards declined to give any specific information about the positives, other than to characterize them as minor.

But despite that characterization, a number of racing officials, veterinarians, and regulators are increasingly concerned that the recent spate of positives for the drug have raised the possibility that DMSO is being used by some horsemen to enhance performance in ways the drug had not previously been administered.

One concern is that milkshakes - concoctions of electrolytes that are pumped directly into a horse's stomach - are being laced with DMSO and administered on backstretches despite a campaign over the past three years to eradicate the treatments, which are banned. Another concern is whether horsemen are injecting powerful solutions of DMSO directly into horses' veins on race day to numb any aches and pains or mixing DMSO into washes that are squirted into a horse's mouth before a race.

DMSO, a Class 5 medication that is rarely targeted by drug-testing labs, is one of the oldest medications in racing, a colorless liquid that is a by-product of wood pulp used as a commercial solvent. In racing, it is most commonly used as a topical dressing in the form of a paste applied to a horse's legs to treat soreness. In recent years, veterinarians said, intravenous injections of the drug have increasingly been used to treat the symptoms of equine protozoal myeloencephalitis - the virus that can cause coordination problems in horses - and to treat bleeding.

According to Florida's Division of Pari-Mutuel Wagering, which regulates the sport, a total of eight DMSO positives were reported in Florida in 2001, including positives for Standardbred horses. In 2002, the total number was 12.

Charlie Camac, a track steward at Gulfstream, said that the six positives this year were "not a big deal" and that he knew nothing about an injectable form of the drug or the use of DMSO in milkshakes or mouthwashes.

"I'm not worried about it at all," Camac said Friday. "This is a therapeutic medication. It is not performance enhancing."

In response to the positives, Gulfstream's stewards put a notice on the track's overnight sheet warning horsemen that the finding of DMSO is "a violation." The notice told horsemen that "a topical dressing" can result in a positive.

Horsemen's officials and the state drug-testing lab director, Dr. Cindy Baker, have taken issue with the language used by the stewards, saying that the positives called this week could not have been the result of an application of DMSO on a horse's skin.

"They didn't discuss with the lab why they put that out," Dr. Baker said last week, referring to the overnight sheet. "I don't know where they got that information. If you have a positive test, I would be very skeptical of anyone who says they only put this on a horse's legs."

In Florida, the drug-testing laboratory uses a type of screen called thin-layer chromatography to detect DMSO. The screen is less sensitive than other drug tests, and it is used to test for DMSO so that trainers and veterinarians who are using "leg paint," as topical applications are called, do not get called for positives, Baker said. The test is used year-round, and no changes have been made recently that would account for the six recent positives, Baker said.

Kent Stirling, the executive director of the Florida Horsemen's Benevolent and Protective Association, said that the recent positives indicated that horsemen could be using DMSO orally - in a milkshake or mouth wash - or in an injection "very close to a race."

The trainers who were fined denied that they used the drug in a milkshake or in an injection. Gorham said that he uses DMSO as leg paint on race day "to loosen them up before they go over."

Falzone said he had "never" used DMSO on the horse who had tested positive for the drug. "I don't know where the horse got DMSO," he said on Friday. "I don't even use the stuff. We didn't use any jugs [an intravenous injection] on him, and I do know some people who do that, mix the DMSO into the jug. But not me."

Falzone said that the horse who tested positive had received a mouthwash before the race. "I don't know if there was any DMSO in that," he said.

Hunter said he used a small amount of DMSO when he rubbed the horse who tested positive on the morning of the race. "Obviously the test they are using is more sensitive," Hunter said.

DMSO has several unique properties that make it effective. In paste form, it can carry other medications across the skin and into joints, and it is commonly used in combination with corticosteroids and antibiotics to avoid sticking a needle into a horse's leg.

According to veterinarians, DMSO is often injected to treat the symptoms of equine protozoal myeloencephalitis, or EPM, a sometimes fatal disease caused by a virus that attacks the central nervous system.

"It supposedly reduces the edema in any neural tissues," said Dr. Rick Arthur, a California veterinarian who is a past president of the American Association of Equine Practitioners. "I've had some trainers become convinced that horses travel better after being treated. And I know one of them was a horse that didn't even have EPM."

Dr. Gary Norwood, a Louisiana-based veterinarian, said that injectable DMSO was widely prescribed several years ago.

"It was kind of a fad diagnosis three or four years ago," Norwood said. "If you couldn't find anything else wrong with the horse, if he was a little funky behind, you said he had EPM, when really the horse just had sore hocks or ankles or shins. So you injected them."

Concern about injectable DMSO stretches back to late 2001, when some regulators discussed reclassifying it because it is considered much more powerful as a painkiller than the paste form. Those efforts eventually fizzled out after regulators decided that they could not reliably determine from a positive test how DMSO was administered, according to Rick Sams, the director of Ohio's drug-testing lab who participated in the discussions.

The discussions about reclassifying DMSO were motivated by a letter sent to racing officials by Rudy Garrison, the state veterinarian in Oklahoma, who said that trainers were injecting DMSO to kill pain within 48 hours of a race and, in some cases, injecting the drug on three consecutive days just before a race.

The prospect of DMSO use in a milkshake has startled some regulators and horsemen's officials who are concerned that more and more trainers may be turning to the electrolyte solutions because of the difficulty in enforcing rules prohibiting the practice. Most of the ingredients of a milkshake - baking soda, water, sugar - are innocuous and not subject to any testing. The only way to detect a milkshake is to catch someone in the act of administering it.

Milkshakes, which are pumped directly into a horse's stomach through a tube snaked down the horse's nose, delay the buildup of lactic acid in muscles, a way of forestalling the effects of fatigue. A horse that is administered a milkshake will not necessarily run faster, but it is believed that the milkshake will allow a horse to carry its speed for a longer period of time.

Efforts to ban milkshakes began in earnest in late 1999 after Kentucky officials discovered that the state's regulations did not ban the concoctions. Since then, most states have passed rules that ban the use of nasal gastric tubes on race day, Florida included.

Regulators said they were uncertain what effect a DMSO-drenched milkshake or mouthwash could have on a horse, but they said they believe that the DMSO would penetrate the stomach lining and be distributed throughout the bloodstream as a painkiller.

Dennis Lee, the chairman of the Nebraska Racing Commission, said that some regulators and scientists believe that DMSO use may also have a negative impact on drug-testing because it can lead to an increase in urine production, diluting a post-race sample or even clouding test results.

"The jury is still out on whether use of DMSO in either its old paste form or the new injectable form can adversely affect testing," said Lee, who called the new uses a threat to DMSO's reputation as "this old, benign drug."

Dr. Ron Jensen, the equine medical director of the California Horse Racing Board and an adviser to the RCI, said on Friday that regulators will likely take another look at DMSO if the speculation surrounding its new uses are true.

"It would certainly merit a reconsideration of the drug's classification if new evidence emerges about how it is being used," Dr. Jensen said.