Scopolamine (l-hyoscine) identifications, often in small-number clusters, have been reported worldwide in performance horses over the last 30. years. Scopolamine is an Association of Racing Commissioners International (ARCI) class 3, penalty class B, substance with potential to affect performance. As such, scopolamine identification(s) in race or performance horses can result in significant penalties for the connections of the horse(s). Reviewed here is the worldwide distribution of scopolamine containing plants (primarily Datura spp.), with estimates of their potential toxicity to horses through dietary and/or environmental exposure. Also reviewed are the basic pharmacology of scopolamine and its precursor, urinary concentrations following feedstuff exposure, and the probable pharmacological/forensic significance of such findings.Based on an overview of the world literature on scopolamine, the expected characteristics of inadvertent environmental exposure are also presented with a view to making clear the potential of scopolamine identifications, with or without atropine, as a direct and expected outcome of both the worldwide distribution of scopolamine-containing plants and the sensitivity of modern equine drug testing. It is of particular interest that only 2/30 reported post-event equine identifications of scopolamine have been associated with atropine, suggesting that failure to identify atropine is not a biomarker of pharmaceutical administration of scopolamine. Available quantitative information associated with scopolamine identifications is consistent with the 75. ng/mL regulatory threshold for scopolamine currently used in Louisiana racing in the USA and the 30. ng/mL reporting threshold in effect in European racing.
|Number of pages||8|
|State||Published - Mar 2014|
Bibliographical noteFunding Information:
Published as paper 415 from the Equine Pharmacology, Therapeutics and Toxicology Program at the Maxwell H. Gluck Equine Research Center and Department of Veterinary Science, University of Kentucky. The information reported in this paper is part of a project of the Kentucky Agricultural Experiment Station (Manuscript 13-14-125) and is published with the approval of the Director. This work was made possible by research support from The National Horsemen’s Benevolent and Protective Association and the Alabama, Arizona, Arkansas, Canada, Charles Town (West Virginia), Florida, Iowa, Indiana, Kentucky, Louisiana, Michigan, Minnesota, Nebraska, Ohio, Oklahoma, Ontario (Canada), Oregon, Pennsylvania, Tampa Bay Downs (Florida), Texas, Washington State, and West Virginia Horsemen’s Benevolent and Protective Associations and the Florida Horsemen’s Charitable Foundation, the Oklahoma Quarter Horse Racing Association and Neogen Corporation.
ASJC Scopus subject areas
- Animal Science and Zoology
- Veterinary (all)