U.S. Public Health Service Policy

The U.S. Public Health Service (PHS) Policy on Humane Care and Use ofLaboratory Animals, originally drafted by the National Institutes of Health in 1973 and extended to all PHS activities in 1979, today incorporates the changes in the Public Health Service Act (PHS Act) mandated by the Health Research Extension Act of 1985, (Public Law 99-158). This law applies to any research institution that receives funds from PHS, of which the National Institutes of Health (NIH), the major funding body for biomedical research, is a component.

The PHS Policy is based on the U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research and Training, drafted by the Interagency Research Animal Committee, with representatives from all Federal agencies that fund biomedical research. Whenever U.S. government agencies develop requirements for testing, research, or training. procedures involving the use of vertebrate animals, the following nine (9) principles must be considered; and whenever these agencies actually perform or sponsor such procedures, the responsible Institutional Official must ensure that these principles are adhered to.

I. The transportation, care, and use of animals should be in accordance with the Animal Welfare Act and other applicable Federal laws, guidelines, and policies.

II. Procedures involving animals should be designed and performed with due consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society.

III. The animals selected for a procedure should be of an appropriate species and quality and the minimum number required to obtain valid results. Methods such as mathematical models, computer simulation, and in vitro biological systems should be considered.

IV. Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative. Unless the contrary is established, investigators should consider that procedures that cause pain or distress in human beings may cause pain or distress in other animals.

V. Procedures with animals that may cause more than momentary or slight pain or distress should be performed with appropriate sedation, analgesia, or anesthesia. Surgical or other painful procedures should not be performed on unanesthetized animals paralyzed by chemical agents.

VI. Animals that would otherwise suffer severe or chronic pain or distress that cannot be relieved should be painlessly killed at the end of the procedure or, if appropriate, during the procedure.

VII. The living conditions of animals should be appropriate for their species and contribute to their health and comfort. Normally, the housing, feeding, and care of all animals used for biomedical purposes must be directed by a veterinarian or other scientist trained and experienced in the proper care, handling, and use of the species being maintained or studied. In any case, veterinary care shall be provided as indicated.

VIII. Investigators and other personnel shall be appropriately qualified and experienced for conducting procedures on living animals. Adequate arrangements shall be made for their in-service training, including the proper and humane care and use of laboratory animals.

IX. Where exceptions are required in relation to the provisions of these Principles, the decisions should not rest with the investigators directly concerned but should be made, with due regard to Principle II, by an appropriate review group such as an institutional animal care and use committee. Such exceptions should not be made solely for the purposes of teaching or demonstration.


The PHS policy, last revised in 2002, is broader than the Animal Welfare Act in that it covers all species of vertebrate animals, including rats, mice and birds, and it covers all research that is funded by the National Institutes of Health (NIH). The Office of Laboratory Animal Welfare (OLAW) at NIH is the agency that is responsible for enforcement of this policy.

In order to receive NIH support for activities involving animals, institutions covered by the PHS policy must submit a written document called an Animal Welfare Assurance of Compliance (or “assurance”) to NIH, which describes how the institution will comply with all the regulations covering animals used in research.

The Animal Welfare Assurance is approved for a period of up to 4 years. It provides details of the institution’s commitment to humane care and use of animals. It includes such things as the institutional policy regarding the care and use of animals; lines of authority within the institution; details concerning the Institutional Program for Animal Care and Use, including responsibilities of veterinarians and IACUC; a listing of approved Animal Facilities; a listing of members of the IACUC; and whether the institution has achieved accreditation through AAALAC (See below.). Each year, via an annual report, the institution provides an update to OLAW about any changes that have occurred in the institution’s animal care and use program.

OLAW approval of an institution’s Assurance Statement commits the institution, its officials, committees, investigators, and any of its other agents to full compliance with the provisions of the PHS Policy. In addition, approval commits the institution to comply with the US Government Principles for the Utilization and Care of Vertebrate Animals, the Guide for the Care and Use of Laboratory Animals, and where applicable, the Animal Welfare Act.
The PHS Policy is based on a concept of enforced self-regulation. Once an institution has prepared an Animal Welfare Assurance and the Assurance has been approved by OLAW, the institution is in a position to regulate itself. If the institution fails to self-regulate, the approval of the Assurance may be restricted or withdrawn by OLAW and funding to the research may be jeopardized.

The PHS Policy is delineated in The Guide for the Care and Use of Laboratory Animals (known as the “Guide“), which was first developed in 1963 as a manual for research facilities receiving public funding for research using animals. It is written by experts in laboratory animal care and is published under the auspices of the Institute for Laboratory Animal Research of the National Academy of Sciences. The Guide is available in several languages.

The eighth and latest edition of the Guide, published in 2011, sets specific standards for the care and use of laboratory animals, including aquatic species for the first time. It addresses key concepts in laboratory animal care and use; the Animal Care and Use Program, including institutional responsibilities; husbandry and housing standards; veterinary care; and physical plant specifications.

The Guide states its purpose is “to assist institutions in caring for and using animals in ways judged to be scientifically, technically, and humanely appropriate. It is also intended to assist investigators in fulfilling their obligation to plan and conduct animal experiments in accordance with the highest scientific, humane, and ethical principles.”

The Guide demonstrates a shift toward performance standards, which emphasize outcomes, as opposed to engineering standards, which are prescriptive and may not allow sufficient flexibility or professional judgment to deal with unique circumstances. Recommendations in the Guide are based on published data, scientific principles, expert opinion, and experience with methods and practices that are consistent with high-quality, humane animal care and use. Extensive references found at the end of each chapter and in the appendices are key features of the Guide.