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Principle 3 of the U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training states that “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”. In addition, federal regulations stipulate that elimination or reduction of unnecessary pain/distress must be considered when preparing research applications. These ideas, commonly referred to as the “3 R’s” (i.e., replacement, refinement, and reduction), were originally articulated by Russell and Burch (1959), and are important considerations for all animal research studies.

ARC Application:

For those protocols that involve animals in Pain Category D (Pain/distress relieved by the use of appropriate anesthetics, analgesics, tranquilizers or by euthanasia) and/or E (Pain/distress can not be relieved by use of anesthetics, analgesics, or tranquilizers, as the use of these agents would interfere with the experimental design), the Committee requires completion of the Pain Category and Pain Literature Search sections.

In the Pain Category section, Questions #3A-C address the concepts of replacement (#3A), refinement (#3B), and reduction (#3C). When addressing these questions, the Committee asks that you focus your response on why each of these concepts is not an acceptable alternative for the proposed research. For example:

  • When answering Question #3A, your response should focus on why the proposed species cannot be replaced with a phylogenetically lower species or a non-animal model.
  • Similarly, when addressing Question #3B, the response should discuss why the proposed painful and/or distressful experiments cannot be refined to further minimize the potential for pain and/or distress.
  • Finally, in your response to Question #3C, please discuss why the number of animals requested for the three-year period of the protocol cannot be further reduced.

Pain Literature Search:

According to PHS Policy IV.C.1.a, the Guide for the Care and Use of Laboratory Animals (the Guide p. 10), and USDA Animal Welfare Act Regulations §2.31(d)(1)(i) “procedures involving animals will avoid or minimize discomfort, distress, and pain to the animals.” Further, in order to meet the above-mentioned regulatory requirement and in accordance with UCLA’s Animal Welfare Assurance on file with the National Institutes of Health Office of Laboratory Animal Welfare (OLAW), the Committee must ensure that the “principal investigator has considered alternatives to procedures that may cause more than momentary or slight pain or distress to the animals, and has provided a written narrative description of the methods and sources used to determine alternatives were not available.”

In the Pain Literature Search section, the Committee requests that you document your most recent search for alternatives. Noting that the intent of the search is to identify potential procedural refinements, the Committee highly recommends that your search strategy include a combination of the animal model being used, keywords specific to the proposed painful and/or distressful procedures, and refinement terminology.

For example, a search strategy for a mouse protocol that utilizes sleep deprivation to study changes in activity in the hippocampus may include the following combinations:

  • Mouse and sleep deprivation and welfare
  • Mouse and sleep deprivation and (stress or distress)
  • Mouse and sleep and hippocampus
  • Sleep and hippocampus and vitro
  • Sleep deprivation and alternative

When you complete the Pain Literature Search section, please specify under Question #2 the different combinations of keywords used to determine that acceptable alternatives are not available.

Please see the UCLA ARC website and the USDA Animal Care Policy #12 for more information.

If you have any questions regarding the information included in this email, please contact the OPRS/ARC staff at x66308 or