The effects of drugs on equine performance and the use of elisa tests in equine medication control

Since the turn of the century stimulant drugs have been used in attempts to influence the performance of horses. More recently, non-steroidal anti-inflammatory drugs have been used with the goal of restoring normal performance in horses with minor, musculoskeletal problems. These uses of medication have led to attempts to experimentally define the effects of drugs on equine performance. Classic performance trials in which small numbers (10) of horses are treated with drugs and their “maximal” performance compared with control values have yielded little useful data. This is because these experiments cannot detect less than a 4% improvement in equine performance, and none of the drugs tests have been able to produce a supra-maximal improvement in performance of this magnitude. However, if the test is made sub-maximal, such as gallop tests, then some workers have reported improvements in “performance.” The use of simple behavioral models allows one to readily characterize the effects of drugs in horses. However, like the sub-maximal output experiments, these experiments do not answer the question of whether or not these drugs affect performance. On the other hand, they may lay the groundwork for studies on larger numbers of racing horses, which appears to be the only satisfactory approach to studies on the effects of drugs on equine performance. The increased potency of drugs used to affect equine performance has led to a need for extremely sensitive testing methods. We have recently developed a series of simple one step ELISA tests for drugs in racing horses that can detect drugs or drug metabolites at nanogram and subnanogram concentrations in equine blood and urine. These tests are particularly effective in pre-race testing and also increase the effectiveness of post-race testing for many medications in racing horses. Additionally, antibodies to commonly used therapeutic medications have been raised which may permithedevelopment of rapid, sensitive, and economical quantitative assays for many medications used in racing horses.