The Prepuce (Figure 15.1)
This is the cutaneous sheath that covers the distal extremity of the flaccid penis. It comprises an inner and an outer lamina that are continuous with one another at the
preputial orifice.
The outer layer is continuous with the skin covering the body of the penis. The space between the prepuce and the body of the penis is the preputial cavity. When the penis is erect, the prepuce retracts to expose the glans penis and the distal part of the body of the penis.15.6.1 The muscles of the prepuce
There are paired muscles attached to the prepuce both cranially and caudally. The cranial preputial muscles act as a sling for the cranial end of the prepuce and seem responsible for keeping the preputial orifice closed.
The caudal preputial muscles insert into the internal lamina of the prepuce and probably retract the prepuce. In the ox these muscles may be absent and yet the prepuce is still retractable.
15.6.2 The blood supply of the prepuce
The prepuce is vascularised by the dorsal artery and vein of the penis and by paired branches of the caudal superficial epigastric vessels.
15.6.3 Species variations of the prepuce
Horse (Figure 15.1): The prepuce differs from that of the other domestic mammals in that it consists of two folds, one inside the other. The inner fold is the preputial fold and its orifice is the preputial ring. The main opening is the preputial orifice. During erection both folds are stretched out to cover the shaft of the penis.
Ruminants (Figure 15.4): In the ox the preputial tube is long, and in the sheep it is relatively short.
Pig (Figure 15.7): There is a dorsal preputial diverticulum of the cranial part of the preputial cavity. It contains a foul-smelling liquid that has to be avoided during evisceration after slaughter. The diverticulum is rudimentary in young pigs.
Dog and Cat (Figures 15.9 and 15.10): There are no special features.