Comparing the efficacy of dextrose, mannitol, and saline solutions in male rabbits' chemical castration

Chemical castration offers a noninvasive way to sterilize male animals without surgical complications. An ideal chemical castration agent should be affordable, effective with a single injection, free of side effects, and without negative impacts on animal welfare. Because there is limited research on chemical castration in rabbits, we aimed to investigate the histopathological and hormonal effects of intra-testicular injections of dextrose, mannitol, and saline solutions in male rabbits. Nine adult rabbits were divided into three equal groups. Under anesthesia, 50% dextrose, 20% mannitol, or 0.9% saline was injected bilaterally into the testicles, with the volume of each solution determined by the width of each testicle. Sixty days after the intra-testicular injections, the rabbits underwent orchiectomy. All testicular tissues were examined histopathologically. Serum testosterone levels were assessed on days 0 and 60. Histopathological examination showed a significant decrease in the quality and maturity of the seminiferous tubules and spermiogenesis index, as well as an increase in histopathological changes in the testis of the saline-receiving group compared to other groups (p < 0.05). Except for the percentage of mature testicular seminiferous tubules, there was no significant difference between the mannitol- and dextrose-receiving groups (p > 0.05). Intra-testicular injections of any of the solutions did not significantly affect testosterone levels (p > 0.05). Our study showed that intra-testicular injection of saline, unlike dextrose and mannitol, can cause significant testicular tissue damage without side effects. Consequently, 0.9% saline may have potential as a chemical sterilization agent in rabbits.