Evaluation of intratesticular injection of glycerol for nonsurgical sterilization of dogs

Abstract

Objective - To determine efficacy of intratesticular injection of glycerol as a means to sterilize dogs. Animals - Six 2- to 4-year-old sexually intact male dogs. Procedure - Testicular volume, serum testosterone concentration, and number of sperm in ejaculate were determined before and at weekly intervals for 12 weeks following intratesticular injection of a 70% glycerol solution (1 ml/testis). Testicular tissue specimens for histologic evaluation were obtained 4, 8, and 12 weeks following injection. Results - Number of sperm in ejaculate following glycerol injection was not significantly different from number before injection. Compared with preinjection values, serum testosterone concentrations were significantly less 5, 9, and 10 weeks following injection, although libido and ejaculate characteristics were unchanged. Testicular swelling was evident 24 to 48 hours following injection, and testicular volume decreased starting on week 5 following treatment. Seminiferous tubules and evidence of normal spermatogenesis were detected in testicular biopsy specimens obtained from all dogs 12 weeks following injection. Conclusions and Clinical Relevance - Intratesticular injection of a 70% glycerol solution did not result in azoospermia and sterility in dogs.