Ashdown R R, David J S, Gibbs C
Vet Rec. 1979 May 12;104(19):423. doi: 10.1136/vr.104.19.423.
Six young bulls (two Friesian, two Charolais, one polled Devon and one North Devon) that had never served successfully, showed good libido but lacked penile erection. In five of these bulls, the short flaccid organ was not protruded during attempted service. Radiography of the cavernous bodies and veins of the penis in the living animal demonstrated major venous drainage of the corpus cavernosum penis (ccp) by the dorsal venous system in all cases. This was not seen in normal bulls. Radiography and anatomical preparations of post mortem specimens showed that the ccp was drained by the dorsal venous system throughout the length of the organ. Proximally, the cavernous spaces of the ccp anastomosed with those of the corpus spongiosum penis (csp) and were drained by numerous small veins. Distally, a system of larger veins, not seen in normal bulls, drained into left and right sides of the dorsal venous system. No microscopical abnormalities of spermatozoa or of testes were found, but there was a marked lack of spermatozoa in the caudae epididymides. The evidence suggests that abnormal venous drainage of the ccp may have been the immediate cause of impotence in these bulls.
六头从未成功配种过的年轻公牛（两头弗里斯兰牛、两头夏洛来牛、一头无角德文牛和一头北德文牛），性欲良好但阴茎无法勃起。在其中五头公牛中，试图配种时短小疲软的阴茎并未伸出。对活体动物阴茎海绵体和静脉进行的放射造影显示，所有病例中阴茎海绵体（ccp）主要通过背侧静脉系统进行静脉引流。正常公牛未见此种情况。对死后标本进行的放射造影和解剖显示，整个阴茎长度范围内，阴茎海绵体均通过背侧静脉系统引流。在近端，阴茎海绵体的海绵间隙与阴茎海绵体（csp）的间隙吻合，并通过许多小静脉引流。在远端，有一个正常公牛未见的较大静脉系统，汇入背侧静脉系统的左右两侧。未发现精子或睾丸有微观异常，但附睾尾部明显缺乏精子。证据表明，阴茎海绵体异常静脉引流可能是这些公牛阳痿的直接原因。
