Equine Health Update EHU Vol 20 Issue 03 - Page 20

EQUINE | NHRA Excerpts NHA LABORATORY WARNING ON HORSERACING PROHIBITED SUBSTANCES WHICH ARE CONTAINED IN READILY AVAILABLE PREPARATIONS A very large proportion of the substances which are prohibited in horseracing are those substances that reduce the pain of injury and associated inflammation. Responsible and controlled treatment with anti- inflammatory, antipyretic and analgesic substances play an important role in the correct recovery procedure. From a welfare perspective, the use of such substances as a masking agent is considered to be cruel as they may well aggravate an underlying injury. Humans also experience such pain with injuries such as cuts, abrasions, bumps, sprains and strains. Since humans are in a position to self-medicate using substances responsibly, there is a significant need for such substances to be available in preparations that are accessible in shop fronts and that are affordable. Problems arise inadvertently when such preparations, available without the requirements of medical consultation and prescription, enter the stable yard. The ease in obtaining these preparations does not suitably emphasize the fact that they are prohibited in racing. It is also unclear what constitutes a prohibited substance dose for a horse when using a preparation intended for humans and how this could result in a prohibited substance positive. Within this document a warning is issued with regard to the use of such prohibited substances and preparations that are readily available. When these preparations are used in the horse they enter the bloodstream including those that are topically administered. This affects the horse, not only where it was administered, but also systemically (within 20 other parts of the body). It is critical that the dose and elimination rate of the particular substance is carefully investigated and considered, with the required veterinary guidance and advice, in combination with a sufficient withdrawal safety margin. • Salicylic acid and salicylic acid (salicylate) derivatives: These preparations typically contain either salicylic acid or acetylsalicylic acid (e.g.Aspirin), methyl salicylate (e.g. Sloan Deep Heat and Rigly’s Horse Liniment) or dimethylamine salicylate (e.g. Reparil gel). The withdrawal period of such substances is recommended to be at least 36 hours. If repeated doses or high doses are used then this period must be increased. • Dimethyl sulfoxide (DMSO): This is an oily substance and it is an analgesic and anti- inflammatory. This substance however also forms part of some topical preparations, with the function to increase the absorption of other substances. The withdrawal period for DMSO prior to racing is at least 48 hours. • Paracetamol: This natural pharmaceutical is contained in some components of horse feed. As a result it is found in the specimens of most horses. Pharmaceutical preparations of paracetamol include a variety of pain (headache) and antipyretic (fever reducing) human medications. Paracetamol is not recommended for therapeutic use in horses. As a high dose is required for a desired effect in the horse, the administration of paracetamol may result in a highly elevated level of this substance, which would result in a positive finding. • Equine Health Update •