THE “ILLEGAL” DRUGS IN RACE HORSES

The “illegal” drugs are drugs whose actions are considered to render them unsuitable under any circumstances for use in horses that are being raced, and whose use is therefore banned. They are mostj commonly listed as the stimulants, depressants, local anesthetics, narcotics, and tranquilizers. Because these drugs are considered to clearly influence the performance of a horse, or to make the horse more dangerous to ride or handle, they are banned in essentially all racing jurisdictions around the world.
Because these drugs produce their effects in the horse by acting on nervous tissue, this section opens with a brief description of the brain of the horse and how these drugs act there. Having outlined the theoretical basis for the actions of these drugs, we then point out the problems of studying these drugs in practice. In particular the problems with the usual horseman’s approach to the study of drug effects in horses are highlighted, and more specialized methods are shown to be necessary.
Having outlined the basic mechanisms of action of these agents and outlined how they can be studied, we then begin a consideration of individual agents. Chapter 11 deals with the classic central nervous stimulants of the amphetamine-caffeine type, drugs whose pharmacology is unexpectedly difficult to study in the horse. The second group of drugs studied are the naifcotic analgesics, the drugs whose actions are easy to study in the horse but whos detection can be troublesome. The last group of stimulant drugs that we will discuss are the so-called dopaminergic stimulants, of which apomorphine is jthe best known and most dramatic example.
Among the tranquilizers, acepromazine, a typical phenothiazine tranquilizer, and reserpine, a long-acting tranquilizer, are the most widely used. Other agents whose use in the horse are less well characterized, such! as the minor tranquilizers, are also discussed. The section ends with a chapter on the various ways of producing local anesthesia used in racing, including local anesthetic drugs, neurectomies, and icing.