USDA perspective on environmental enrichment for animals.

This article provides a brief historical background of the events and circumstances that led to the 1985 Animal Welfare Act (AWA) amendments. It describes the development of the regulations promulgated by the US Department of Agriculture (USDA) in 1991 as a result of these amendments, the reasoning given for the proposals, and the revisions that were made during the process. Information is included on USDA implementation of the regulations regarding exercise for dogs and environmental enhancement for nonhuman primates. Also mentioned briefly are the requirements for socialization of marine mammals and space requirements for certain other regulated warm-blooded species. These requirements apply to animal dealers (breeders and brokers), exhibitors, commercial transporters, and research facilities. The standards for exercise and environmental enhancement were different from any others previously contained in the AWA regulations, and required more research and understanding of species-specific needs by the regulated community. Finally, this article describes some of the initiatives being undertaken by the research community and USDA-Animal and Plant Health Inspection Services (APHIS)-Animal Care to provide the necessary education and guidance indicated by the violation history data.