Impotence in the boar 2: Clinical and anatomical studies on impotent boars

Six boars were deficient in penile erection and incapable of intromission, but produced ejaculates containing spermatozoa. In five of these boars impotence was primary, but one boar had served normally for two seasons before showing secondary impotence. Sexual libido was good in two, moderate in two and poor in two of these animals. Post mortem studies on the reproductive tracts revealed no abnormalities except in the penes. In one of the boars with primary impotence, the penis showed an abnormal type of spiral deviation during simulated erection, but there was no abnormality in the venous drainage of the organ. In the other five boars, injection experiments revealed venous drainage of the corpus cavernosum penis (ccp) into the dorsolateral (left) tributary of the v dorsalis penis. In four cases, the apical cavernous spaces of the ccp communicated with the vascular spaces of the corpus spongiosum glandis. No direct communications with the corpus spongiosum penis (csp) were demonstrated but the csp was injected from the ccp indirectly, by way of the dorsal venous system. It is suggested that these abnormalities may have been the immediate cause of impotence in these five boars. This possibility is discussed in relationship to the processes of erection and ejaculation and to various clinical signs shown by these animals. The abnormalities of venous drainage were thought to be developmental in origin and the condition may be inherited.