An appreciation of normal reproductive anatomy is essential to the competent physical examination of the stallion’s reproductive tract. If you are involved in breeding, then you should be familiar with what is considered normal so you know when something is wrong. This information will also help mare owners make informed decisions about a particular stallion which might have physical problems outside the norm.

The genital tract of the stallion consists of two testes and attached epididymides contained within a scrotum; paired deferent ducts (or ductus deferens), which traverse the spermatic cord to enter the abdomen through the inguinal rings, then penetrate the genital fold to terminate in the pelvic urethra; four distinct accessory genital glands; a musculocavernous penis; and its protective prepuce. In this article, we will review each anatomical feature and describe its function. The language at times might seem technical, but if you are going to deal with breeding stock, you might as well familiarize yourself with proper anatomical names so you can understand the discussions around you.

Basic Anatomy

Scrotum–The scrotum of the stallion, situated high between the hind limbs, is slightly pendulous (hanging downward) and has a globular shape. It contains two distinct pouches, each investing and protecting a testis, epididymis, spermatic cord, and cremaster muscle. The scrotum plays a vital role in testicular thermoregulation (more on this in a moment)