Drug testing is about to move into the 21st Century for horseracing. Research findings at the University of Kentucky’s Gluck Equine Research Center could make the use of urine in post-race drug testing a thing of the past within a very short time. Urine has been the body fluid of choice in drug testing because the horse’s kidney concentrates whatever is in the blood. Therefore, every drug in the horse’s system is concentrated at least 50-fold by the kidney, and fluid (urine) is excreted in a large volume for sampling. The disadvantages are that urine testing relates poorly to blood concentration, and drugs sometimes can be found for a long time in urine.

Blood is a much more satisfactory medium, but the concentrations of drug are much smaller. This makes detection and quantitation more challenging. An ideal method would be highly sensitive and specific and require only a small volume of sample. This method now has arrived.

New liquid chromatography mass spectrometry mass spectrometry (LC-MS-MS) offers an exquisitely sensitive test to laboratories. The new testing equipment, while expensive, is highly specific, very sensitive, and virtually eliminates background readings of “other” substances that might confuse results.

With this new technology demonstrated in the laboratory, there now is available to the industry a test sensitive enough to use blood instead of urine in drug detection for most agents. For horse owners, it means making cutoffs much fairer because it eliminates the inherent variability of testing urine. Drugs such as Bute are given in gram quantities and the threshold is set in micrograms per ml (parts per million). This new technology extends testing for substances that are given in milligram quantities or less and tested in picograms or parts per trillion.

This technology can fulfill two primary goals of the Kentucky Equine Drug Testing and Research Council and the National Thoroughbred Racing Association Equine Drug Testing and Research Initiatives to improve uniformity in methodology of drug testing and offer a level playing field for horses