The Rules of Racing don’t allow anything to be present at levels that could affect performance on raceday. There is no definitive list of individual substances; rather substances are classified based on their effect on the horse’s body systems. This ensures that both current and as yet undeveloped substances can be covered by the same Rules. In practical terms the laboratory testing protocols routinely applied in British horseracing use expertly developed databases that will detect around 2,000 different substances. These may be substances commonly used for therapeutic treatment or substances where we have intelligence of possible use or abuse. These databases are constantly being updated as new drugs or new uses of existing drugs are developed. So if a new or previously unidentified substance is found it will still be identified and action taken.