Temporary reversible sterilization can be safely and effectively performed in dogs using hormonal down-regulation. Progestogens have been used for estrus suppression in dogs for over 50 years. The gonadotropin-releasing hormone (GnRH) agonist deslorelin is available as 4.7 mg and 9.4 mg implants labelled for reversible sterilization in dogs lasting 6 and 12 months, respectively. Permanent sterilization can be achieved non-surgically in dogs via an intratesticular injection. The safety and efficacy on non-surgical methods for preventing reproduction in dogs will be explained.