Drug contamination of the equine racetrack environment: a preliminary examination.

Advances in analytical technology now make it feasible to detect and confirm exceptionally low concentrations (pg to fg/mL) of drugs and their metabolites in equine biological fluids. These new capabilities complicate the regulatory interpretation of drug positives and bring into question the fair application of medication rules. Such approaches and policies are further complicated by the possibility that drug positives may arise from contamination of the equine environment on the backstretch of the race track. This manuscript provides data demonstrating that the general environment of the backstretch in which horses live is contaminated with therapeutic drugs and drugs of human origin. The major contaminants are nonsteroidal anti-inflammatory drugs, such as flunixin, phenylbutazone and naproxen, present in the soil in stalls, on stall surfaces, in the dust that circulates and in the lagoon waters that accumulate on the backstretch. The presence of caffeine and cotinine suggest other possible vectors for contamination by humans. Concentrations of these compounds as well as their frequency of occurrence are provided.