Animal welfare regulations in preclinical studies are in place to ensure the humane treatment of animals used in research, and to minimize their suffering. These regulations are designed to ensure that animal models used in preclinical studies are treated humanely, and that their use is justified and necessary.

In the United States, the Animal Welfare Act (AWA) is the primary federal law that governs the use of animals in research. The AWA sets standards for animal care and housing, and requires that animal research be approved and overseen by an institutional animal care and use committee (IACUC).

In addition to the AWA, there are other regulations and guidelines that provide guidance on the ethical use of animals in research, such as the Guide for the Care and Use of Laboratory Animals and the Public Health Service Policy on Humane Care and Use of Laboratory Animals.

The ethical use of animals in research requires that researchers consider the three Rs: replacement, reduction, and refinement. Replacement involves the use of non-animal models, such as cell cultures or computer models, instead of animals whenever possible. Reduction involves minimizing the number of animals used in research, while still obtaining meaningful results. Refinement involves reducing the pain and distress experienced by animals during research, by improving animal care and reducing the invasiveness of procedures.

Overall, the use of animals in preclinical studies is governed by strict regulations and guidelines to ensure the humane treatment of animals and the ethical use of animal models. Researchers must comply with these regulations and guidelines, and make every effort to minimize the use of animals, minimize their suffering, and obtain meaningful and relevant results from preclinical studies.