Efficacy of Intratesticular Glycerol Injection as Male Cat Contraception in Comparison with Two Surgical Approaches

Abstract

The objectives of the current study were to compare the use of a single bilateral intratesticular injection of 2 different volumes of glycerol 70% (0.5 and 1.0 mL) as a method of chemical sterilization and the application of 2 surgical procedures (orchiectomy and vasoligation). Animals were classified into 4 groups. Group 1:10 cats were subjected to a conventional bilateral orchidectomy. Group 2:6 cats were subjected to a bilateral vasoligation of the testicular blood supply without removing the testicles. Group 3:7 cats were subjected to a single intratesticular injection of 0.5 mL glycerol bilaterally and Group 4:7 cats were subjected to a single intratesticular injection of 1.0 mL glycerol bilaterally. Serum testosterone concentration (ng/mL) and average testicular length (cm) were measured just before (control) and weekly after orchiectomy (only serum testosterone concentration), vasoligation, and intratesticular treatment for 3 consecutive weeks. After 2 months from testicular vasoligation (group 2) and intratesticular administration (group 3 and 4), castration was performed for all cats. The epididymal sperm count and the histopathological findings were recorded for all groups after the orchidectomy. In group 2 serum testosterone level was significantly (P ˂ .01) decreased from (4.14 ± 1.10 ng/mL) before vasoligation (control) to (1.71 ± 0.34 ng/mL) 3 weeks postoperation. In group 4 a significant (P ˂ .01) decrease in serum testosterone concentration was recorded 2 and 3 weeks postinjection (1.41 ± 0.31 and 1.32 ± 0.21 ng/mL, respectively). There was a significant decrease in the testicular length 1 week after the vasoligation (group 2) and the testicular treatment (group 4) compared with preoperative controls of the 2 groups. Besides, the epididymal samples collected from groups (2 and 4) showed azoospermia. In conclusion, a bilateral intratesticular injection of 1.0 mL glycerol (70%) as a chemical method of tomcat sterilization can replace the surgical orchidectomy besides being less invasive and less traumatic and gave better results than using the intratesticular injection of 0.5 mL glycerol.

Keywords: Glycerol; Intratesticular injection; Orchidectomy; Tomcat sterilization.