Alteratives comprise a number of drugs of importance to the horse owner. It has been previously stated that they alter the nutrition of the body and bring about certain desired results, not only in relation to disease, but also in the process of training the horse in health for particular purposes. These results are obtained without any marked action upon any particular organ. It is supposed that alteratives act by inducing minute chemical changes in the economy which are quite inappreciable by ordinary methods of observation, but yet of a more or less lasting character. If given medicinally, their action may remain permanent, but an animal artificially "prepared" or got up for show purposes, and maintained in show condition by their aid, will often fade or lose his bloom when after long use they are discontinued.

The glossy skin beloved of horse dealers and exhibitors is often the result of a course of arsenic, antimony, sulphur, and nitre, which are chiefly employed on account of their action upon the skin. Sulphuric acid (oil of vitriol) is the chief agent of the teamster, who too often relies on such mixtures to impart sleekness to the coat, which can only be otherwise obtained at considerable expenditure of manual labour.