Refinement in the literature: Searching for environmental enrichment

The term environmental enrichment became more common among animal caretakers in zoo and research settings after the passage of the 1985 amendments to the United States Animal Welfare Act which introduced the concept of psychological well-being of nonhuman primates and required exercise for dogs. The standards promulgated by the US Department of Agriculture in response to the new mandates placed an emphasis on individual facilities developing targeted exercise and enrichment programs based on an understanding of species-specific needs. Interestingly, although originally focused on nonhuman primates, the concept of environmental enhancement (or enrichment) spilled over into the housing of other species as well. This review will examine early research into environmentally enriched housing and how that same concept is applied in various management settings today. In addition to these new requirements, the 1985 amendments specified that pain and distress must be minimized in scientific research and that principal investigators much consider alternatives to procedures that may cause more that momentary or slight pain or distress. One method of examining potential alternatives is a comprehensive literature search for alternatives, defined as the 3Rs (reduction, refinement, or replacement). Often, the refinement portion of a literature search is either neglected or forgotten. This paper will also discuss methods of searching the literature to locate information on housing refinements, particularly the provision of environmental enrichment.