UNILATERAL TESTICULAR DEGENERATION IN DOGS ADVERSELY AFFECTS SPERMATOZOA CHARACTERISTICS IN THE TESTIS AND EPIDIDYMIS

Résumé

Testicular degeneration (TD) is associated with poor fertility in affected dogs. The study investigated the specific effects of unilateral testicular degeneration (UTD) on spermatozoal parameters in the testes and epididymides of dogs. Ten sexually mature (7-12 months old) Nigerian indigenous breed of dogs comprising 5 normal dogs (N; both testes normal and present in the scrotum) and 5 dogs with UTD (one normal scrotal testis and one degenerated scrotal testis) were used for the study.The testes and epididymides were removed via orchidectomy and sperm analyses (total and progressive motility, vitality, total abnormalities and concentration) were performed. The samples were grouped as N1 (right normal testis); N2 (left normal testis); UTD-N (normal testis in dogs with UTD); UTD-D (degenerated testis in dogs with UTD). Data were analysed using one-way ANOVA. The UTD-D group had significantly lower (p<0.001) epididymal sperm total and progressive motility, vitality and concentration, higher total sperm abnormalities (p<0.001) and lower testicular sperm concentration (p<0.01) compared to the contralateral UTD-N and the N testes. The UTD-N group also had significantly lower epididymal sperm total motility (p<0.01) and progressive motility (p < 0.05), and higher total abnormalities (p<0.05) compared to the N groups. Our study demonstrated that UTD in dogs adversely affected spermatozoa in the affected testis and epididymis. There was also evidence of compromised spermatozoa in the testis and epididymis contralateral to the degenerated testis. Taken together, these sperm abnormalities are likely to have adverse effect on the fertility of affected dogs.