A Cluster of Trace-Concentration Methamphetamine Identifications in Racehorses Associated with a Methamphetamine-Contaminated Horse Trailer: A Report and Analysis

Three low concentration methamphetamine “positive” tests were linked to use of a methamphetamine-contaminated trailer to transport the affected horses. This incident establishes methamphetamine as a human-use substance that can inadvertently enter the environment of racing horses, resulting in urinary methamphetamine “positives;” an interim regulatory cut-off of 15 ng/mL for methamphetamine in post-race urine is proposed