The action of medicines will be found in another part of this work (pp. 1 and 12 of this volume), and it is proposed in this chapter to deal with the various methods of administering them which custom or convenience requires in the treatment of our patient the horse.

Medicines are conveyed into the body by one of several channels.

They may be given by the mouth as draughts, boluses, or electuaries, or by the rectum in the form of enemata, or they may be injected beneath the skin (subcutaneous injection), or directly into one or another of the superficial veins (intra-venous injection). In the form of vapour they are also inhaled, and in particular instances are injected into the trachea or windpipe (intra-tracheal injection).