Medicine may enter the body through any of the following designated channels

Medicine may enter the body through any of the following designated channels: First, by the mouth; second, by the air passages; third, by the skin; fourth, by the tissue beneath the skin (hypodermic methods); fifth, by the rectum; sixth, by the genito-urinary passages; and, seventh, by the blood (intravenous injections).

By the mouth. Medicines can be given by the mouth in the form of solids, as powders or pills; liquids, and pastes, or electuaries.

Fonte: Diseases of the Horse