Detection and quantification of low levels of benzoylecgonine in equine urine.

The research article discusses the detection and measurement of benzoylecgonine, a metabolite of cocaine, in horse urine, amid concerns of environmental contamination and its impact on the competitive horse racing industry.

Objective and Context

• The study was undertaken against the backdrop of increasing concerns about trace amounts of benzoylecgonine (BE) found in race horses urine due to environmental contamination, such as cocaine residues present on US paper currency. Cocaine, a potent psychoactive substance, has no usage in equine veterinary practice.
• The Illinois Racing Board established new rules in 2005 stipulating a threshold level of 150 ng/mL for BE in horse urine to protect horse trainers from severe penalties arising due to non-intentional presence of trace amounts of this metabolite. Repeated breaches of this rule would result in incrementally increasing fines for the trainers.

Methodology

• Over a two-year period, a total of 19,315 urine samples were collected from winning horses (both harness and thoroughbred) at race tracks in Illinois for routine drug screening using Enzyme-Linked Immunosorbent Assay (ELISA).
• The presence of BE was confirmed through Gas Chromatography/Mass Spectrometry (GC/MS) in 28 urine samples or 0.14% of the total samples collected.

Results and Conclusion

• Among the detected BE cases, the concentration range for harness horses (21 detections) ranged from less than 5 to 91 ng/mL, while for thoroughbred horses (seven detections) it ranged from 7 to 52 ng/mL.
• Interestingly, the research results indicated that the laboratory has yet to report concentrations of BE that exceed the established threshold concentration of 150 ng/mL, suggesting that environmental contamination may not be as rampant or consequential as initially feared.