When does stress turn into distress? The U.S. government wants to clarify that question, and over the last 4 months it's received 2600 pieces of advice about whether to adopt a proposed definition. The decision on whether and how to define distress could dictate the care of millions of lab animals, and some scientists worry that monitoring distress could interfere with research.
Under the Animal Welfare Act, the U.S. Department of Agriculture (USDA) must seek to "minimize pain and distress" of laboratory animals. But USDA regulations to date have "focused on pain and have not given equal consideration to distress," says Ron DeHaven, deputy administrator of USDA's Animal and Plant Health Inspection Service (APHIS). To remedy that situation, APHIS came up with a working definition of distress: "a state in which an animal cannot escape from or adapt to the internal or external stressors or conditions it experiences, resulting in negative effects on its well-being." In July it asked for public comments, the first step in a long process that will likely culminate in new regulations.
Animal welfare groups support the idea of new regulations. The Humane Society of the United States, for example, has proposed a system, similar to one in the United Kingdom, that would group animals that undergo procedures without painkilling drugs into three classes based on whether the pain is mild, moderate, or severe.
Some researchers argue that existing regulations can be refined to make the USDA's monitoring system more objective and systematic. But others worry that tinkering with the rules will create undue paperwork and a lot of uncertainty about how to design experiments. The definition of distress is "vague and could lead to widely varying, highly subjective interpretations," the Federation of American Societies for Experimental Biology wrote USDA. "There are no simple physiological or behavioral criteria to mark the point where an animal that experiences stress becomes distressed."