Progestin use in mares

Abstract

Progesterone is in constant fluctuation throughout the lifespan of the horse. As a key regulator of the hypothalamic-pituitary-gonadal
axis, progesterone is involved in numerous aspects of reproduction. Synthetic analogs of progesterone, deemed progestins, are
widely available to industry to act as progestogenic within the reproductive tract, although few are bioactive in the horse. Utilized to
suppress estrous, delay ovulation, maintain pregnancy, and for behavioral modifications, progestins are one of the most common
class of pharmaceuticals in veterinary medicine. In this review, we discuss the progestins available to equine industry, their efficacy,
pharmacokinetics, and potential side effects following treatment.