02/18/2003 1:00AM

First positive tests for EPO


NEW YORK - Horses in Texas and New York have tested positive for the banned blood-doping drug erythropoietin, or EPO, according to regulators in those states.

The positives are the first to be acknowledged for EPO, which is banned in every racing state. The positives are being called as a result of a new test that has been quietly circulated among many racing laboratories over the past six months.

In Texas, six Thoroughbred horses that raced at Sam Houston Race Park in January recently tested positive for EPO, according to Paula Flowerday, the executive director of the Texas Racing Commission. The positives were first reported by the Dallas Morning News.

In New York, the director of the state's racing laboratory at Cornell, Dr. George Maylin - who co-developed the new test - said on Tuesday that a "small percentage of horses" have tested positive under an experimental program, but that the results had not been announced yet.

Aqueduct racetrack in New York recently added a notice to its overnight sheet warning trainers about use of EPO and other related substances, such as darbepoietin. The overnight warning had first appeared in July 2002, when the test had not yet been distributed, but was soon removed.

Texas regulators have not taken disciplinary action against the trainers of the horses, according to Flowerday, citing the limitations of the test used to detect the drug. Flowerday also said that further details about the tests were confidential.

"The trainers were interviewed by our investigators, and the owners were sent a letter," Flowerday said. "It was not intended to scare anyone, or to warn anyone about possible disciplinary action in the future. It was to let people know that their horses had a positive reaction to the test and inform them about the dangers of the drug."

In humans, EPO stimulates the spleen to manufacture oxygen-carrying red blood cells, and it has been widely abused in cycling and other endurance athletic events. Very little is known about its effect on horses, but anecdotal evidence has suggested that horses who were injected with EPO could suffer heart failure or, with regular injections, develop anemia.

Rumors about the illegal use of EPO in horses have circulated for years. Drug-testing scientists in the U.S. have failed, however, to develop a test that can detect a specific administration of EPO to a horse within a certain time frame, complicating efforts by regulators to use the test in a way that would stand up in court.

The test currently in circulation can only detect antibodies produced by the horse's immune system in response to an injection of the human form of the drug. In short, the test can only determine that a horse had been "exposed" to EPO at some time within the past three months, scientists said.

Flowerday said that the Texas racing lab had been using the test for two or three months "for research to determine whether or not we have a problem with EPO in this state."

Dr. Maylin said that results of the Cornell testing program in New York would likely be released in mid-March.

"We've tested a large number of horses, and we've been waiting for the dust to settle before we go forward," Dr. Maylin said. "The simple fact is, if the drug is going to be verboten, then someone is going to have to do something about enforcing it."