A respected resource for decades, the "Guide for the Care and Use of Laboratory Animals" has been revised by a committee of experts, based on input from scientists and the public. The Guide incorporates recent research on commonly used species, including farm animals, and includes extensive references. It is organized around major components of animal use: institutional policies and responsibilities - the committee discusses areas that require policy attention: the role and function of the Institutional Animal Care and Use Committee, protocols for animal care and use, occupational health and safety, personnel qualifications, and other areas; animal environment, husbandry, and management - the committee offers guidelines on how to design and run a management program, addressing environment, nutrition, sanitation, behavioral and social issues, genetics, nomenclature, and more; veterinary care - the committee discusses animal procurement and transportation, disease and preventive medicine, and surgery. The Guide addresses pain recognition and relief and issues surrounding euthanasia; physical plant- the committee identifies design and construction issues, providing guidelines for animal-room doors, drainage, noise control, surgery, and other areas. The "Guide for the Care and Use of Laboratory Animals" provides a framework for the judgments required in the management of animal facilities - a resource of proven value, now updated and expanded. This revision will be important to researchers, animal care technicians, facilities managers, administrators at research institutions, policymakers involved in research issues, and animal welfare advocates.