Chemical castration in dogs using calcium chloride: effects on testicular hemodynamics and semen characteristic and serum levels of testosterone

Dog overpopulation and stray dogs are global issues that are detrimental to public health and animal welfare. Thus, the goal of the current study was to provide alternatives for surgical castration. Therefore, calcium chloride was employed in this study, which might be an option for castration. Ten dogs were divided into two groups of five: a calcium chloride-treated group and a control group. The treated group received a single bilateral intratesticular injection of 1 ml of sterile saline containing calcium chloride dihydrate (CaCl2•2 H2O) at a dose of 20 mg/kg per testicle. While the control group was treated with 1 ml of sterile saline solution, Semen and blood collection, as well as Doppler ultrasonography, were routinely carried out every week on days 0, 7, 14, 21, and 28 in order to evaluate the impact of the injection on semen parameters and testicular blood flow. The testicular volume and echogenicity in the CaCl2-treated group were significantly (P < 0.001) lower in weeks 2 through 4 than in the control group. Furthermore, in canine semen, CaCl2 dramatically decreased the amount, motility, and viability of sperm. When compared to vehicle-control animals, azoospermia was seen 2 weeks after the injection and persisted for the end of the study. The testes of all dogs were surgically removed at 30 days post-injection, and testes were put in 10% neutral buffered formalin for tissue processing. When compared to the control group, the average weight of testes in the chemical groups was dramatically reduced. Significant decreases in spermatogenic processes, necrosis, and degeneration of seminiferous tubules packed with necrotic debris, and fibrosed interstitial tissue, necrosed and calcified Sertoli, and Leydig cells were seen 30 days after CaCl2 injection. There was a significant decrease in testosterone levels compared to day 0 before CaCl2 injection and the control group. From weeks 1 through 4, there was a substantial decrease in both peak systolic velocity (PSV) and end-diastolic velocity (EDV) values (P < 0.001) following a single intratesticular injection of CaCl2. The resistance index (RI) and pulsatility index (PI) showed the opposite tendency. Based on the histopathological and semen evaluations in this investigation, the study concludes that a single intratesticular injection of CaCl2 appears to be a practical and generally applicable approach for chemical sterilization of dogs.