Yeast-induced hyperalgesia: an method of inducing joint pain by the injection of yeast typically brewer's yeast into the paw of a rat which will result in oedema and subsequent hyperalgesia. A method used to test the effects of anti-inflammatory and antinociceptive drugs on acute pain.

Yohimbine: also known as quebrachine, corynine and aphrodine, a naturally occurring indole alkaloid ((16α,17α)-17-hydroxyyohimban-16-carboxylic acid methyl ester) obtained from Rauwolfia serpentina and Corynanthe johimbe and bark from related trees. It is a non-subtype selective, competitive α2-adrenoceptor antagonist and vasodilator. It is used as a pharmacological tool in the study of α2-adrenoceptors and has been considered to be an aphrodisiac due to its vasodilator actions. It is used in veterinary pharmacology, however, to reverse the effects of xylazine (an α2-adrenoceptor agonist used as an analgesic in cows, horses and pigs) and possibly amitraz (also an α2-adrenoceptor agonist).

Yucatan micropig: a strain of micropig^© (Sus scrofa) developed originally from the Yukatan pig at the Colorado State University Swine Laboratory in 1978. It is easy to manage and is used as a laboratory animal largely to test the effects of drugs on the cardiovascular system.