PLEASE NOTE THAT A MORE RECENT EDITION OF THIS TITLE IS AVAILABLE IN THE LIBRARY

The perineum is made up of the structures which make up the boundary of the pelvic outlet. It extends externally from the dorsal aspect of the scrotum or vulva to the base of the tail; its lateral margins extend to the skin covering the tubers ischii and superficial gluteal muscles. The deep portion is delineated by the ischial arch ventrally, the third coccygeal vertebra dorsally and, in the dog, by the sacrotuberous ligament laterally. Due to the absence of sacrotuberous ligament in the cat the lateral margins are less well defined. The perineum essentially surround the anal and urogenital canals. Within the perineum the most important structures are those which make up the pelvic diaphragm; namely levator ani and coccygeal muscles. This chapter looks at Anatomy and physiology; Diagnostic approach; and Clinical disorders of the perineum and anus.