Abstract

Managing genetically and demographically healthy captive populations within relevant husbandry and welfare guidelines depends on a foundation of cooperation and shared information. Three services are seen as so essential to managing zoo populations they are all partially funded through the American Zoo and Aquarium Association (AZA): animal records and the development of the Zoological Information Management System (ZIMS); population analysis and the development of species masterplans; and monitoring contraceptive use, advancing product development and providing contraceptive recommendations. In 1999 AZA folded the Contraception Advisory Group into the AZA Wildlife Contraception Center at the Saint Louis Zoo. The Contraception Center’s co-directors, Dr. Cheryl Asa and Ingrid Porton, are employees of the Saint Louis Zoo while the program manager is currently funded through AZA. The Contraception Center is a readily available resource for contraceptive information and advice for the entire AZA community. We encourage all AAZV veterinarians and their staff to become familiar with the services and contraceptive products offered through the center, provide input regarding unmet contraceptive needs and/or issues that require additional research, and consider participating in relevant research trials.

The Contraception Center’s website (www.stlzoo.org/contraception) is the most up-to-date source of contraception information available to the practicing veterinarian. The contraception recommendations, which are based on published research results from center-sponsored research trails and analysis of the contraception database, are updated annually and published on the website in a searchable format. Details on how to obtain contraceptive products supplied through the center or submit reproductive tracts to Dr. Linda Munson are included in the Recommendations. The center maintains a “Contraceptive Hotline” (314-781-0900 ext. 384) and “Hot-Email Address” (contraception@stlzoo.org) for questions and issues not addressed in the published recommendations. Additional useful and in-depth contraceptive information can also be found in the center’s recently published book.¹

The center makes contraceptive products available to the zoo community through commercial partners, including Wildlife Pharmaceuticals, Peptech Animal Health, and Purina Mills. The center then monitors contraceptive use and maintains a database in compliance with FDA regulations and to serve as a basis for FDA reports. MGA in implant form remains the most widely used contraceptive in U.S. zoos, but is also available incorporated in an herbivore diet or as a liquid for addition to the regular diet or to treats. These oral formulations are used predominantly in ungulates. Although MGA has been effective in almost all the species tested, it and other synthetic progestins are associated with potentially severe side effects, especially in carnivores.

Alternatives to MGA and the other steroid-based methods include the zona pellucida vaccine, provided by Dr. J. Kirkpatrick and used primarily in hoofstock. The GnRH agonists such as leuprolide and deslorelin have the advantage of being potentially effective in males as well as females, and they are available as either a tiny implant or injectable implant. Trials to date indicate that these agonists can be effective contraceptives in females of perhaps all mammalians species, but do not suppress reproduction in male ungulates or marsupials. Deslorelin is being used successfully in 23 carnivore species, 13 primates, and 4 ungulates, as well as dolphins, fur seals, and a single tree shrew.

One of the center’s main objectives is to foster communication and exchange of information with the people who manage and care for captive animals. Survey data are used to monitor various aspects of efficacy and to identify problems with application so that we can either correct the problems or search for alternative products. The Contraception Center is well positioned to integrate disparate contraceptive results and experiences that, together, can alert the zoo community to problems, early successes, or areas for further research. Veterinarians, animal managers and caretakers play a critical role in the success of the center by responding to surveys and reporting their observations.

Literature Cited

1.  Asa, C.S., and I.J. Porton. 2005. Wildlife Contraception: Issues, Methods and Application. Johns Hopkins University Press: Baltimore, MD.