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Proceedings for Pain Management and Humane Endpoints

Animal Welfare Act - Requirements for the Minimization of Pain and Distress

W. R. DeHaven
US Department of Agriculture
 Animal and Plant Health Inspection Service, Animal Care

While recognizing the continuing need to use animals in biomedical research, Congress made clear their intent to minimize animal pain, distress, and discomfort in the 1985 amendment to the Animal Welfare Act. References to minimizing or eliminating pain are found in Section 13 of the Animal Welfare Act. In this section, Congress mandated the Secretary of Agriculture to promulgate regulations to ensure that animal pain and distress are minimized. Further, it requires principal investigators to consider alternatives to painful or distressful procedures, and states that, in any practice which could cause pain to animals, a veterinarian must be consulted in planning of the procedures to ensure the appropriate use of pain-relieving medications. Any withholding of pain-relieving medications or euthanasia should be limited to that which is scientifically necessary and shall continue for only the necessary period of time. Section 13 also requires every research facility regulated under the AWA to have an Institutional Animal Care and Use Committee (IACUC), giving this committee responsibility to review practices involving pain to animals for compliance with the regulations. Finally, there is a requirement in the Act for each research facility to provide for the training of research or testing methods that minimize or eliminate the use of animals or limit animal pain or distress.

The implementing regulations for these requirements from Section 13 of the Act are found in Subpart C, Part 2, Title 9, Code of Federal Regulations, and it is assumed the audience is well familiar with these particular sections of the regulations. To further clarify the regulations, USDA's Animal Care division has developed two policy statements, or interpretive rules, dealing specifically with the issue of pain and distress in laboratory animals.1 Policy #11 addresses the issue of painful procedures, defined as, "any procedure that would be expected to cause more than slight or momentary pain or distress in a human being." The policy provides three specific examples of potentially painful procedures. A terminal procedure is a painful procedure which is alleviated by the use of anesthesia. Use of Freund's Complete Adjuvant can cause a painful response from slight to severe depending upon the product, the exact procedures and the species involved. With ocular and skin irritancy testing, the dosing procedure is generally not painful, rather the painful reaction is caused by the product itself.

In terms of potentially distressful procedures, the policy gives, again, three examples: food or water deprivation beyond that which would normally precede pre-surgical preparation; noxious electrical shock from which an animal cannot immediately escape; and paralysis or immobility in a conscious animal. Again, these are examples that, in many circumstances, would be considered distressful.

Policy #11 goes on to state that animals exhibiting signs of pain, discomfort or distress are expected to receive appropriate relief unless scientific justification is provided in the proposal and approved by the IACUC. The important message here is the default position requires the use of pain-relieving medications unless there is scientific evidence to demonstrate that they would interfere with the validity of end results. In years past, the default position has been to assume pain-relieving drugs might interfere with the results, and therefore withhold them when in doubt. However, Animal Care's position since the early 1990's has been the opposite; that is, scientific evidence must prove that the use of pain-relieving drugs would hinder the end result of the procedure to justify withholding their use.

Potentially painful procedures, such as terminal surgical procedures, are required to be reported in the USDA Annual Report in "Column D." For those unfamiliar with the Annual Report, "Column D" is the classification for animals which are subjected to painful procedures wherein the pain is alleviated through the use of pain-relieving drugs. In those cases where there is a potential for pain -- such as with terminal surgical procedures -- a search for alternatives is required. The basis for this interpretation is found in Section 2.31(d)(ii) of the regulations which states that the PI must consider alternatives to procedures that may cause more than momentary or slight pain or distress to the animals. Further, the preamble written with the final rule for these regulations (Federal Register, August 31, 1989, page 36117) states, "a procedure in which pain is relieved is still considered to be a painful procedure, and the provisions of the Act which address the conduct of painful procedures apply."

Policy #12, "Written Narrative for Alternatives to Painful Procedures," is an interpretive rule that is intended to provide Animal Care inspectors and the regulated industry a better understanding of what we believe constitutes adequate documentation of a good faith search for alternatives. This rule is based on the statutory requirement in Section 13 of the AWA to minimize pain and distress to animals during experimentation as well as the requirement for principal investigators to consider alternatives to painful or distressful procedures. Again, the Federal Register (August 31, 1989, page 36130) clarifies that the IACUC, as an agent of the facility, must satisfy itself that alternatives were adequate considered. Accordingly, Animal Care places the burden on the IACUC to gather sufficient information upon which to make that determination. Thus, if the PI uses an electronic literature search as the basis for making the required assurance, then the date of the search, the source(s), key words, and date range will normally provide the IACUC with the requisite information.

This policy includes the expectation that principal investigators (PI) will not stop searching simply because they are unable to find a non-animal model. Rather, Animal Care would expect the concepts of refinement and reduction to be applied whenever and wherever possible in order to minimize animal pain and distress if it cannot be eliminated.

This policy does not, however, rule out means other than an electronic database search of the literature to satisfy the requirement to conduct a search. It is recognized that, in some unique circumstances, there can be a better method of conducting the search and giving the IACUC the necessary assurance. Thus, the policy allows the PI to provide an alternate search strategy that describes the "methods and sources used to determine that no alternatives were available to the painful or distressful procedure." Again, Animal Care would be interested in assuring that the IACUC had received sufficient information to reasonably assure itself that a good faith effort was made to search for alternatives.

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