Testicular function of scrotal testes after the cryptorchidectomy in dogs with unilateral cryptorchidism.

Abstract

Cryptorchidectomy was performed in 6 adult dogs with unilateral cryptorchidism. In these dogs, semen samples were collected weekly from 2 weeks before cryptorchidectomy till 24 weeks after the operation. Peripheral venous blood samples were collected from all the dogs at intervals of 4 weeks, and spermatic venous blood samples and testicular tissue specimens were obtained at the time of the removal of cryptorchid and scrotal testes. In the scrotal testes the testosterone level of spermatic venous plasma was lower, and the number of germ cells in the seminiferous tubules was smaller than those in the testis of the normal dogs at the time of cryptorchidectomy. However, semen volume and number of sperms increased gradually, and sperm abnormality decreased after the operation. Semen quality became close to that of the normal dog 20 weeks after the operation or later. Furthermore the plasma testosterone levels and the number of germ cells increased to the same as those in the normal dog at 24 weeks after the operation. Therefore, it was concluded that in the dogs with unilateral cryptorchidism the cryptorchid testis disturbed the testicular function of the scrotal testis.