Temporary Sterilization

Suprelorin (active ingredient is Deslorelin)
6 mg dose - After 21-27 days all testosterone has been stopped.  Stops testosterone and sperm production fro 6-12 months. Testosterone levels are at normal range at 52 weeks.  Sperm and testes are fully back to normal after 60 months

Authorized in EU

Good article on how to inject this drug by a zoo

EU: http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/veterinary/medicines/000109/vet_med_000189.jsp&mid=WC0b01ac058008d7a8

Permenant Sterilization

 Drug Name: Esterilsol
FDA Approved
 

Zinc Neutering