A new testing method could detect some prohibited performance-enhancing drugs in racehorses.Photo credit: Slooby, Wikimedia CommonsDoping in the horseracing industry has spurred regulations banning performance-enhancing drugs, as well as calls for an anti-doping agency in the U.S. But as in human sports, testing for certain kinds of prohibited substances has been a challenge. Now scientists report in the American Chemical Society journal Analytical Chemistry a new detection method that could help anti-doping enforcers determine whether a horse has received certain substances. 

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To give their animals an edge on the track, some horse trainers and veterinarians might administer a single substance, a cocktail of hormones, hormone-mimicking compounds or other drugs. Most are prohibited in the racing world, but catching violators can in some cases be difficult with conventional methods. Existing techniques directly test for the original compounds administered to an animal or their unique metabolites or byproducts. But some of these substances can get processed and eliminated by the animal quickly, making the window for detection very short. George Ho Man Chan, Terence See Ming Wan and colleagues are currently investigating unconventional ways to increase the chances of catching cheaters. 

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The researchers have identified seven biomarkers in urine that potentially indicate whether a horse has been given aromatase inhibitors, a class of compounds also used by bodybuilders to help regulate hormones and get an edge on the competition. Testing for the changes in these naturally-occurring biomarkers in horse urine could reveal the administration of the substances for about 95 to 195 hours after injection. That's 2 to 2.5 times longer than conventional screening methods. Being able to find evidence for the administration of these drugs for two or more days longer than before could increase the chances that rule-violators will be caught.  With further validation studies, this method could be developed into a useful screening tool for detecting the use of aromatase inhibitors in horses.