The penis is covered by a triangular penile sheath that opens backwards; it is about long. The scrotum is located high in the perineum with the testicles in separate sacs. Testicles are long, deep and wide. The right testicle is often smaller than the left. The typical mass of either testicle is less than ; during the rut the mass increases from . The Cowper's gland is white, almond-shaped and lacks seminal vesicles; the prostate gland is dark yellow, disc-shaped and divided into two lobes.