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National Research Council (US) Committee for the Update of the Guide for the Care and Use of Laboratory Animals. Guide for the Care and Use of Laboratory Animals. 8th edition. Washington (DC): National Academies Press (US); 2011.

Cover of Guide for the Care and Use of Laboratory Animals

Guide for the Care and Use of Laboratory Animals. 8th edition.

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1Key Concepts

This edition of the Guide for the Care and Use of Laboratory Animals (the Guide) strongly affirms the principle that all who care for, use, or produce animals for research, testing, or teaching must assume responsibility for their well-being. The Guide is created by scientists and veterinarians for scientists and veterinarians to uphold the scientific rigor and integrity of biomedical research with laboratory animals as expected by their colleagues and society at large.

The Guide plays an important role in decision making regarding the use of vertebrate laboratory animals because it establishes the minimum ethical, practice, and care standards for researchers and their institutions. The use of laboratory animals in research, teaching, testing, and production is also governed or affected by various federal and local laws, regulations, and standards; for example, in the United States the Animal Welfare Act (AWA 1990) and Regulations (PL 89-544; USDA 1985) and/or Public Health Service (PHS) Policy (PHS 2002) may apply. Compliance with these laws, regulations, policies, and standards (or subsequent revised versions) in the establishment and implementation of a program of animal care and use is discussed in Chapter 2.

Taken together, the practical effect of these laws, regulations, and policies is to establish a system of self-regulation and regulatory oversight that binds researchers and institutions using animals. Both researchers and institutions have affirmative duties of humane care and use that are supported by practical, ethical, and scientific principles. This system of self-regulation establishes a rigorous program of animal care and use and provides flexibility in fulfilling the responsibility to provide humane care. The specific scope and nature of this responsibility can vary based on the scientific discipline, nature of the animal use, and species involved, but because it affects animal care and use in every situation this responsibility requires that producers, teachers, researchers, and institutions carry out purposeful analyses of proposed uses of laboratory animals. The Guide is central to these analyses and to the development of a program in which humane care is incorporated into all aspects of laboratory animal care and use.


In the Guide, laboratory animals (also referred to as animals) are generally defined as any vertebrate animal (i.e., traditional laboratory animals, agricultural animals, wildlife, and aquatic species) produced for or used in research, testing, or teaching. Animal use is defined as the proper care, use, and humane treatment of laboratory animals produced for or used in research, testing, or teaching.

Laboratory animals or animals: Any vertebrate animal (e.g., traditional laboratory animals, agricultural animals, wildlife, and aquatic species) produced for or used in research, testing, or teaching.

When appropriate, considerations or specific emphases for agricultural animals and nontraditional species are presented. The Guide does not address in detail agricultural animals used in production, agricultural research or teaching, wildlife and aquatic species studied in natural settings, or invertebrate animals (e.g., cephalopods) used in research, but establishes general principles and ethical considerations that are also applicable to these species and situations. References provide the reader with additional resources, and supplemental information on breeding, care, management, and use of selected laboratory animal species is available in other publications prepared by the Institute for Laboratory Animal Research (ILAR) and other organizations (Appendix A).

Animal use: The proper care, use, and humane treatment of laboratory animals produced for or used in research, testing, or teaching.

The goal of the Guide is to promote the humane care and use of laboratory animals by providing information that will enhance animal well-being, the quality of research, and the advancement of scientific knowledge that is relevant to both humans and animals. The Committee recognizes that the use of different species in research is expanding and that researchers and institutions will face new and unique challenges in determining how to apply the Guide in these situations. In making such determinations, it is important to keep in mind that the Guide is intended to provide information to assist researchers, institutional animal care and use committees (IACUCs), veterinarians, and other stakeholders in ensuring the implementation of effective and appropriate animal care and use programs that are based on humane care. Throughout the Guide, scientists and institutions are encouraged to give careful and deliberate thought to the decision to use animals, taking into consideration the contribution that such use will make to new knowledge, ethical concerns, and the availability of alternatives to animal use (NRC 1992). A practical strategy for decision making, the “Three Rs” (Replacement, Reduction, and Refinement) approach, is discussed in more detail below. Institutions should use the recommendations in the Guide as a foundation for the development of a comprehensive animal care and use program and a process for continually improving this program.


The Guide is intended for a wide and diverse audience, including

  • the scientific community
  • administrators
  • IACUCs
  • veterinarians
  • educators and trainers
  • producers of laboratory animals
  • accreditation bodies
  • regulators
  • the public.

The Guide is meant to be read by the user in its entirety, as there are many concepts throughout that may be helpful. Individual sections will be particularly relevant to certain users, and it is expected that the reader will explore in more detail the references provided (including those in Appendix A) on topics of interest.

Members of the scientific community (investigators and other animal users) will find Chapters 1 and 2 (and portions of Chapter 4) of the Guide useful for their interactions with the IACUC, attending veterinarian, and administrators regarding animal care as well as the preparation of animal care and use protocols. Scientific review committees and journal editors may choose to refer to multiple sections of the Guide to determine whether scientists contributing proposals and manuscripts have met the appropriate standards in their planned use of animals. The Guide can assist IACUCs and administrators in protocol review, assessment, and oversight of an animal care and use program. Veterinarians should find Chapters 3 through 5 valuable for their oversight and support of animal care and use. Educators and trainers can use the Guide as a document to assess both the scope and adequacy of training programs supported by the institution. Accreditation bodies will find the Guide useful for evaluating many areas of animal care and use programs not subject to strict engineering standards (see definition below). Finally, members of the public should feel assured that adherence to the Guide will ensure humane care and use of laboratory animals.

Readers are reminded that the Guide is used by a diverse group of national and international institutions and organizations, many of which are covered by neither the Animal Welfare Act nor the PHS Policy. The Guide uses some terminology that is both defined by US statute and denotes a general concept (e.g., “attending veterinarian,” “adequate veterinary care,” and “institutional official”). Even if these terms are not consistent with those used by non-US institutions, the underlying principles can still be applied. In all instances where Guide recommendations are different from applicable legal or policy requirements, the higher standard should apply.


The decision to use animals in research requires critical thought, judgment, and analysis. Using animals in research is a privilege granted by society to the research community with the expectation that such use will provide either significant new knowledge or lead to improvement in human and/or animal well-being (McCarthy 1999; Perry 2007). It is a trust that mandates responsible and humane care and use of these animals. The Guide endorses the responsibilities of investigators as stated in the U.S. Government Principles for Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training (IRAC 1985; see Appendix B). These principles direct the research community to accept responsibility for the care and use of animals during all phases of the research effort. Other government agencies and professional organizations have published similar principles (NASA 2008; NCB 2005; NIH 2006, 2007; for additional references see Appendix A). Ethical considerations discussed here and in other sections of the Guide should serve as a starting point; readers are encouraged to go beyond these provisions. In certain situations, special considerations will arise during protocol review and planning; several of these situations are discussed in more detail in Chapter 2.


The Three Rs represent a practical method for implementation of the principles described above. In 1959, W.M.S. Russell and R.L. Burch published a practical strategy of replacement, refinement, and reduction—referred to as the Three Rs—for researchers to apply when considering experimental design in laboratory animal research (Russell and Burch 1959). Over the years, the Three Rs have become an internationally accepted approach for researchers to apply when deciding to use animals in research and in designing humane animal research studies.

Replacement refers to methods that avoid using animals. The term includes absolute replacements (i.e., replacing animals with inanimate systems such as computer programs) as well as relative replacements (i.e., replacing animals such as vertebrates with animals that are lower on the phylogenetic scale).

Refinement refers to modifications of husbandry or experimental procedures to enhance animal well-being and minimize or eliminate pain and distress. While institutions and investigators should take all reasonable measures to eliminate pain and distress through refinement, IACUCs should understand that with some types of studies there may be either unforeseen or intended experimental outcomes that produce pain. These outcomes may or may not be eliminated based on the goals of the study.

Reduction involves strategies for obtaining comparable levels of information from the use of fewer animals or for maximizing the information obtained from a given number of animals (without increasing pain or distress) so that in the long run fewer animals are needed to acquire the same scientific information. This approach relies on an analysis of experimental design, applications of newer technologies, the use of appropriate statistical methods, and control of environmentally related variability in animal housing and study areas (see Appendix A).

Refinement and reduction goals should be balanced on a case-by-case basis. Principal investigators are strongly discouraged from advocating animal reuse as a reduction strategy, and reduction should not be a rationale for reusing an animal or animals that have already undergone experimental procedures especially if the well-being of the animals would be compromised. Studies that may result in severe or chronic pain or significant alterations in the animals’ ability to maintain normal physiology, or adequately respond to stressors, should include descriptions of appropriate humane endpoints or provide science-based justification for not using a particular, commonly accepted humane endpoint. Veterinary consultation must occur when pain or distress is beyond the level anticipated in the protocol description or when interventional control is not possible.


The Committee for the Update of the Guide believes that the terms set out below are important for a full understanding of the Guide. Accordingly, we have defined these terms and concepts to provide users of the Guide with additional assistance in implementing their responsibilities.

Humane Care

Humane care means those actions taken to ensure that laboratory animals are treated according to high ethical and scientific standards. Implementation of a humane care program, and creation of a laboratory environment in which humane care and respect for animals are valued and encouraged, underlies the core requirements of the Guide and the system of self-regulation it supports (Klein and Bayne 2007).

Animal Care and Use Program

The animal care and use program (the Program) means the policies, procedures, standards, organizational structure, staffing, facilities, and practices put into place by an institution to achieve the humane care and use of animals in the laboratory and throughout the institution. It includes the establishment and support of an IACUC or equivalent ethical oversight committee and the maintenance of an environment in which the IACUC can function successfully to carry out its responsibilities under the Guide and applicable laws and policies. Chapter 2 provides a more expansive discussion of the importance of the Guide and its application to animal care and use programs.

Engineering, Performance, and Practice Standards

Engineering standard means a standard or guideline that specifies in detail a method, technology, or technique for achieving a desired outcome; it does not provide for modification in the event that acceptable alternative methods are available or unusual circumstances arise. Engineering standards are prescriptive and provide limited flexibility for implementation. However, an engineering standard can be useful to establish a baseline and is relatively easy to use in evaluating compliance.

Performance standard means a standard or guideline that, while describing a desired outcome, provides flexibility in achieving this outcome by granting discretion to those responsible for managing the animal care and use program, the researcher, and the IACUC. The performance approach requires professional input, sound judgment, and a team approach to achieve specific goals. It is essential that the desired outcomes and/or goals be clearly defined and appropriate performance measures regularly monitored in order to verify the success of the process. Performance standards can be advantageous because they accommodate the consideration of many variables (such as the species and previous history of the animals, facilities, staff expertise, and research goals) so that implementation can be best tailored to meet the recommendations in the Guide.

Ideally, engineering and performance standards are balanced, setting a target for optimal practices, management, and operations while encouraging flexibility and judgment, if appropriate, based on individual situations (Gonder et al. 2001).

Scientists, veterinarians, technicians, and others have extensive experience and information covering many of the topics discussed in the Guide. For topics on which information is insufficient or incomplete, sustained research into improved methods of laboratory animal management, care, and use is needed for the continued evaluation and improvement of performance and engineering standards.

Practice standard means the application of professional judgment by qualified, experienced individuals to a task or process over time, an approach that has been demonstrated to benefit or enhance animal care and use. Professional judgment comes from information in the peer-reviewed scientific literature and textbooks and, as in many other disciplines, from time-proven experiences in the field (for additional information see Chapter 2). In the absence of published scientific literature or other definitive sources, where experience has demonstrated that a particular practice improves animal care and use, practice standards have been used in determining appropriate recommendations in the Guide. In most situations, the Guide is intended to provide flexibility so that institutions can modify practices and procedures with changing conditions and new information.


Policies commonly derive from a public agency or private entity. They are generally practical statements of collective wisdom, convention, or management direction that are internal to the entity. However, policies may assume broader force when they become the means by which an implementing agency interprets existing statutes (e.g., PHS Policy). Principles are broader in their scope and intended application, and are accepted generalizations about a topic that are frequently endorsed by many and diverse organizations (e.g., the U.S. Government Principles). Procedures (often called “operating procedures” or “standard operating procedures”) are typically detailed, step-by-step processes meant to ensure the consistent application of institutional practices. Establishing standard operating procedures can assist an institution in complying with regulations, policies, and principles as well as with day-to-day operations and management.


Must indicates actions that the Committee for the Update of the Guide considers imperative and mandatory duty or requirement for providing humane animal care and use. Should indicates a strong recommendation for achieving a goal; however, the Committee recognizes that individual circumstances might justify an alternative strategy. May indicates a suggestion to be considered.

The Guide is written in general terms so that its recommendations can be applied in diverse institutions and settings that produce or use animals for research, teaching, and testing. This approach requires that users, IACUCs, veterinarians, and producers apply professional judgment in making specific decisions regarding animal care and use. Because the Guide is written in general terms, IACUCs have a key role in interpretation, implementation, oversight, and evaluation of institutional animal care and use programs.


  1. AWA [Animal Welfare Act] Animal Welfare Act. PL (Public Law) 89-544. 1990. [accessed January 14, 2010]. Available at www​
  2. Gonder JC, Smeby RR, Wolfle TL. Performance Standards and Animal Welfare: Definition, Application and Assessment, Parts I and II. Greenbelt MD: Scientists Center for Animal Welfare; 2001.
  3. IRAC [Interagency Research Animal Committee] U.S. Government Principles for Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training. Federal Register, May 20, 1985. Washington: Office of Science and Technology Policy; 1985. [accessed May 10, 2010]. Available at http://oacu​​/regs/USGovtPrncpl.htm. [PubMed: 11655791]
  4. Klein HJ, Bayne KA. Establishing a culture of care, conscience, and responsibility: Addressing the improvement of scientific discovery and animal welfare through science-based performance standards. ILAR J. 2007;48:3–11. [PubMed: 17170491]
  5. McCarthy CR. Bioethics of laboratory animal research. ILAR J. 1999;40:1–37.
  6. NASA [National Aeronautics and Space Administration] NASA Principles for the Ethical Care and Use of Animals. NPR 8910.1B-Appendix A. May 28. 2008. [accessed May 10, 2010]. Available at http://nodis3​.gsfc.nasa​.gov/displayDir.cfm?t​=NPDandc=8910ands=1B.
  7. NCB [Nuffield Council on Bioethics] The Ethics of Research Using Animals. London: NCB; 2005.
  8. NIH [National Institutes of Health] Memorandum of Understanding Between the Office of Laboratory Animal Welfare, National Institutes of Health, US Department of Health and Human Services and the Office of Research Oversight and the Office of Research and Development, Veterans Health Administration, US Department of Veterans Affairs Concerning Laboratory Animal Welfare. November 2007. Bethesda: Office of Extramural Research, NIH; 2007. Available at http://grants​​/grants/olaw/references​/mou_olaw_va_2007_11.htm.
  9. NIH. Memorandum of Understanding Among the Animal and Plant Health Inspection Service USDA and the Food and Drug Administration, US Department of Health and Human Services and the National Institutes of Health Concerning Laboratory Animal Welfare. March 1, 2006. Bethesda: Office of Extramural Research, NIH; 2006. Available at http://grants​​/grants/olaw/references/finalmou.htm.
  10. NRC [National Research Council] Report on Responsible Science. Washington: National Academy Press; 1992.
  11. Perry P. The ethics of animal research: A UK perspective. ILAR J. 2007;48:42–46. [PubMed: 17170495]
  12. PHS [Public Health Service] Public Health Service Policy on Humane Care and Use of Laboratory Animals. Publication of the Department of Health and Human Services, National Institutes of Health, Office of Laboratory Animal Welfare. 2002. [accessed June 9, 2010]. Available at http://grants​​/grants/olaw/references/phspol.htm.
  13. Russell WMS, Burch RL. The Principles of Humane Experimental Technique. London: Methuen and Co; 1959. [Reissued: 1992, Universities Federation for Animal Welfare, Herts, UK]
  14. USDA [US Department of Agriculture] 9 CFR 1A. (Title 9, Chapter 1, Subchapter A): Animal Welfare. 1985. [accessed January 14, 2010]. Available at http://ecfr​.gpoaccess​.gov/cgi/t/text/text-idx?sid​=8314313bd7adf2c9f1964e2d82a88d92andc=ecfrandtpl=​/ecfrbrowse​/Title09/9cfrv1_02.tpl.
Copyright © 2011, National Academy of Sciences.
Bookshelf ID: NBK54054


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