Contraception General Information
About the AZA Reproductive Management Center's Contraception Research Program and Database
The Reproductive Management Center maintains a database to monitor all contraceptives used in captive wildlife. Because the use of contraceptives that have not been commercially approved by FDA must be considered experimental, IACUC (Institutional Animal Care and Use Committee) approval is needed for compliance with the Animal Welfare Act. The AZA Reproductive Management Center has obtained IACUC approval for MGA implants, MGA Feed, and Suprelorin® implants for zoos participating in these programs. Commercially available products used in wildlife can be considered "extra label use" and do not require IACUC approval.
How to Choose the Appropriate Contraceptive Method
A variety of factors such as efficacy and safety of available methods, the animal's age, behavioral and social factors, the practicality of different delivery systems, and the individual's reproductive status must be considered when selecting an appropriate contraceptive method. It is unlikely that the same birth control method will be the most appropriate choice during all stages of an animal's life. Permanent sterilization or participation in contraceptive studies is encouraged for surplus animals.
Administration of oral contraceptives need only be stopped to initiate reversal. To hasten time to reversal, Suprelorin® and MGA implants can/should be removed. Reversal times for injectables, such as PZP vaccine and Depo-Provera, cannot be manipulated. Time to reversal varies for many reasons. The most basic measure of reversal is when the concentration of the contraceptive compound (or titer, in the case of vaccines) in the body drops below the level necessary for efficacy. However, it is often not possible to measure this event, so confirmation that reversibility has been successful must depend on documentation that ovulatory cycles or sperm production have resumed (in cases where hormonal contraceptives have suppressed ovulation; the PZP vaccine may not interfere with ovulation), and/or diagnosis of pregnancy or birth of young. Many factors other than contraceptives affect ovulation and conception. These include reproductive history, age, health, body weight (very thin or obese animals may not ovulate or conceive) and, of course, fertility of the partner. This information is based on what is known about clearance of the contraceptive from the body and does not take individual history or condition into account.