Animal comfort is a primary concern in how experiments are conducted.
Animal Welfare Act and the Public Health Service Policy on Humane Care and Use of Laboratory Animals require every research proposal to be reviewed by an institutional animal care and use committee or "IACUC." The purpose of IACUC review is to consider the research plan from the animal’s point of view. IACUC approval is not granted until the researcher has shown that he or she has selected the most appropriate species and the minimum number of animals needed to produce scientifically valid results. The researcher must explain why research procedures that might be painful are necessary and what will be done to keep the animals as comfortable as possible. Research may not proceed without this approval. The IACUC also has the authority to halt research in progress if concerns about animal welfare arise.
Most of the time, either the experiment is not painful or else pain-relieving drugs are given as part of the research protocol. A few experiments do involve painful procedures because pain is being studied or drugs would interfere with the research. In such cases, scientists are morally and legally obligated to ensure that the procedures are necessary. The institution will not allow such projects to proceed until the IACUC approves them.
Those who work with research animals — scientists, veterinarians, and animal care technicians — care about them. They recognize that using animals in research is a privilege that carries with it the responsibility to treat those animals humanely. Furthermore, pain and distress can literally change how the body functions, so it is also in the best interest of science to provide good animal care.