The coccygeal artery as a route for the administration of drugs into the reproductive tract of cattle.

A simple procedure is described for cannulating the aorta abdominalis of cattle through the coccygeal artery, and for positioning the tip of the cannula close to the origin of the ovarian artery. When noradrenaline was infused through the cannula there was a rapid increase in the concentration of progesterone in the peripheral blood, whereas the intravenous infusion of the same dose of noradrenaline had little effect. The procedure can be used for endocrinological studies of the reproductive organs and avoids the more costly and potentially damaging procedure of implanting cannulae during a laparotomy.