Testicle descent: stallions compared with bulls
Keywords: bull, stallion, cryptorchid, anatomy, testicle, gubernaculum
This image compares testicular descent in cattle (lower right) and horses (upper left).
This image compares testicular descent in cattle (lower right) and horses (upper left).
Image size: 1425 x 1597px
In bulls, the testicles descend into the scrotum by about the fifth month of gestation. By comparison, testicular descent is only complete in stallions close to the time that they are born. This comparative tardiness in testicular descent may be related to the relatively high incidence of cryptorchidism in stallions.
In bulls, the testicles descend into the scrotum by about the fifth month of gestation. By comparison, testicular descent is only complete in stallions close to the time that they are born. This comparative tardiness in testicular descent may be related to the relatively high incidence of cryptorchidism in stallions.
In comparing the two animals, cryptorchidism is seldom encountered in cattle. In both of these illustrations the gubernaculum has been indicated by red arrows, showing that it is a very large structure in both bulls and stallions; at some point in testicular descent, larger than the testicles themselves. After testicular descent, the gubernaculum regresses to an insignificant ligament between the tail of the epididymis and the parietal vaginal tunic.
