Sterilization of male stray dogs with a single intratesticular injection of calcium chloride: a dose-dependent study.

OBJECTIVE To study a method of chemical sterilization and its efficacy in adult male stray dogs. METHODS Sterilization was performed 45 days after a single bilateral intratesticular injection of calcium chloride (CaCl(2)) at the doses of 5, 10, 15 or 20 mg per testis per kg body weight. RESULTS Histomorphological measures of testes showed total necrosis of testicular tissue at 45 days after an injection of either 10 or 15 or 20 mg CaCl(2) along with fibrosis and hyalinization in seminiferous tubules and interstitial spaces. Infiltration of leucocytes was also observed with the 10- or 15-mg dose. Disintegration of germ cell arrangement in seminiferous tubules and washing out of germ cells from the tubules were noted with the 5-mg dose. Relative organ weight, epididymal sperm count, plasma and intratesticular concentrations of testosterone, testicular activities of Delta(5),3beta-hydroxysteroid dehydrogenase (Delta(5),3beta-HSD), 17beta-hydroxysteroid dehydrogenase (17beta-HSD), glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) and testicular contents of glutathione (GSH) and glutathione disulphide (GSSG) and the ratio of GSH/GSSG, all were declined in each of the calcium chloride treated groups in comparison to the control group. Increases occurred in testicular malondialdehyde (MDA) and plasma concentrations of LH and FSH with each of the treatments by comparison with the control group. Plasma concentrations of cortisol, fasting blood sugar level, blood urea nitrogen as well as packed cell volume (PCV) and total plasma protein were recorded to monitor the changes in chronic stress in the experimental animals. Changes in these parameters were not significant. CONCLUSION An intratesticular injection of CaCl(2) at specified doses could be a suitable method of sterilization in preference to surgical castration of dogs.