Long-term reproductive consequences of no-scalpel vasectomy in beagles

The effects of vasectomy on the reproductive organs in various species are controversial. This study investigated the morphological change and apoptosis of the testis, epididymis, and vas deferens in beagle dogs 12 months after vasectomy. The male beagles were divided into two groups: vasectomized and sham-operated groups (n=5 in each). Histopathological, ultrastructural, and TUNEL evaluation of the changes in the testis, epididymis, and ductus deferens of each animal were conducted 12 months after surgery. The mean lumen diameter, cellular thickness, mean interstitial distance, and lumen area fraction of each seminiferous tubule and ductus epididymis were measured by stereological analysis. The results showed that, compared with the sham-operated group, the seminiferous tubular epithelial cells of the testes in the vasectomized group were disorderly arranged and scattered. Significant atrophy and apoptosis were found in the endothelial cells, and a range of ultrastructural variations were observed in the cells of testes, epididymis, and vas deferens in vasectomized group. It was concluded that complete obstruction of the vas deferens as a traditional contraception method is not absolutely safe in terms of the reversal of fertility in the long run. Techniques of relieving the inner pressure in the vas deferens while maintaining the efficacy of male contraception need to be explored.