Impotence in the bull: (2) occlusion of the longitudinal canals of the corpus cavernosum penis.

Lack of penile erection was diagnosed in nine bulls (Poll Hereford three; Aberdeen Angus two; Friesian two; horned Hereford; Sussex). Five had previously served successfully but four had proved impotent when first put to use. In each bull, the dorsal longitudinal canal of the corpus cavernosum penis (ccp) was occluded by fibrous tissue and this was considered to be the immediate cause of impotence. The ventral canals were also occluded in four bulls. In every case, the lesions were so extensive that treatment would not have been likely to succeed. In two bulls the dorsal canal and the tunica albuginea were ruptured proximal to the sigmoid flexure. Radiography of the cavernous spaces and veins during life, and anatomical injections of post mortem specimens, showed that in four bulls the ccp was drained by the dorsal venous system at or distal to the sigmoid flexure. The aetiology and the diagnosis are discussed and the possible physiological implications of occlusions of the canals are considered in terms of the functional anatomy of the ccp.