Non-isotopic immunoassay drug tests in racing horses: a review of their application to pre- and post-race testing, drug quantitation, and human drug testing.

The research explores the use of non-isotopic immunoassay testing methods in the detection of drug use in racehorses, both before and after races. The methods proved effective in uncovering previously overlooked drug abuse patterns, and can also be adapted for use in human drug testing.

Methodology

• The researchers used two technologies in their testing – Particle Concentration Fluorescence Immuno Assay (PCFIA) and Enzyme Linked Immuno Sorbent Assay (ELISA).
• Both methods were found to be fast, cost-effective, and extremely accurate in detecting several types of illicit substances in horses.
• The drugs these tests were successful in identifying included buprenorphine, oxymorphone, mazindol, sufentanil, and cocaine. These were all being used to gain competitive advantage in horse racing, yet went undetected by the previously-used thin layer chromatography (TLC) testing.

Results and Findings

• The introduction of these testing methods in the Western United States uncovered several patterns of drug abuse among racehorses that had previously gone unnoticed. This led to the suspension of a large number of trainers.
• The poor performance of TLC tests was highlighted by the high rate of false negatives they produced in comparison to the ELISA tests.
• In Illinois, pre-race testing using PCFIA methods discovered signs of acepromazine abuse. Once these horses were identified, post-race samples of their urine confirmed the presence of acepromazine metabolites.
• The researchers also used these tests to quantify permitted medications, phenylbutazone and furosemide, in a fast and cost-effective manner.
• For the drug furosemide, a schedule was developed using immunoassay tests that eliminated the need for a detention barn prior to the race. Similarly, a quick and inexpensive quantitation of phenylbutazone in the blood was achieved using these tests.

Adaption for Human Drug Testing

• The researchers were also able to adapt PCFIA technology for human drug testing, enabling racing authorities to test jockeys and other staff for drug usage.
• These immunoassays were sensitive enough to detect and thus control the abuse of even the most potent drugs available to racehorse trainers.
• In principle, these tests could be developed for any drug within a six-month period, and distributed globally at competitive prices.
• The researchers concluded that non-isotopic immunoassays are the only technological tool sensitive and flexible enough to detect the most potent abused drugs before and after matches, and can be easily adaptable to different drugs.
• Because TLC tests generate a high amount of false negatives, the researchers argue that they are not a credible basis for pre- and post-race testing programs.