Laboratory animals. Researchers pained by effort to define distress precisely

The U.S. Department of Agriculture requested comments earlier this year to help it decide whether to adopt a formal definition of "distress" as part of its responsibilities under the Animal Welfare Act. But the 2600 pieces of advice it received during a 4-month period that ended earlier this month suggest that its job won't be easy. The comments highlight a deep split between animal activists, who see the potential new regulations as a step toward eliminating all painful procedures, and most researchers, who say that the present system is working well and that no major changes are needed.