Animal Research

show/hide words to know

Culture: a growing “soup” of microscopic organisms and the nutrients they need to survive.

Nematode: a worm with an unsegmented cylindrical body that often narrows at each end.

The Nervous System: a network of nerve cells that transmits nerve impulses between parts of the body.

Tissue: A group of similar cells that do a specific job together. Organs are made of groups of tissues.

Vertebrate: the major division of animals that have a backbone (spinal column) which is made up of several different pieces... more

Regulations for Animal Well-being

In response to increased public concern for the treatment and well-being of animals used in research, many new regulations and laws were passed to help protect animals. For example, the Animal Welfare Act in 1966 outlined the minimum standards for the treatment of animals both during and after any research study.

Lab mouse

Scientists follow regulations that determine how they use animals in experiments. Image by Rama.

After the passing of the Animal Welfare Act by the United States, the United Kingdom passed a very similar law, called the Animal Scientific Procedures Act (ASPA). This new law was passed in 1986.

Compared to the guidelines put in to place by the United States, ASPA provided stricter guidelines on how to treat animals. Central to ASPA was the concept of the three R's:


  • When possible, scientists should avoid using vertebrate animals, like lizards, fish, or rabbits and use animals that have a less complex nervous system. These animals might include insects, nematodes, or bacteria. This means that scientists should only use vertebrates if it is absolutely necessary for a specific research study.
  • When possible, research techniques that do not require animals should be used, like tissue culture or computer simulation. This is to limit the number of animals involved in research.


  • Animal well-being should always be kept in mind throughout the research process. This means minimizing any pain or stress for the animal. Animal stress or pain is only allowed if it is absolutely necessary for the outcome of an experiment.
  • Animal welfare includes providing animals with high quality food, a clean living space, and access to an interactive social environment. These requirements promote proper care for the animals during the study.
  • Importantly, these guidelines also tend to provide better scientific results for the researchers. This is because the test animals are in environments with fewer confounding variables like stress, disease, or isolation.


  • Scientists should try to use the smallest number of animal subjects in a given study. By doing so, researchers reduce the need for animal research subjects. It also requires scientists to think more about how to do this, when also may improve the quality of the scientific findings.

The three R's have become central to the current ways of understanding and preserving the ethical treatment of animals in research. You can find more information on these guidelines here.

Additional images via Wikimedia Commons. Image of C. Elegans worm by Heiti Paves.

View Citation

You may need to edit author's name to meet the style formats, which are in most cases "Last name, First name."

Bibliographic details:

  • Article: The Three R’s for Animal Treatment and Well-being
  • Author(s): Patrick McGurrin and Christian Ross
  • Publisher: Arizona State University School of Life Sciences Ask A Biologist
  • Site name: ASU - Ask A Biologist
  • Date published: December 4, 2016
  • Date accessed: June 12, 2024
  • Link:

APA Style

Patrick McGurrin and Christian Ross. (2016, December 04). The Three R’s for Animal Treatment and Well-being. ASU - Ask A Biologist. Retrieved June 12, 2024 from

American Psychological Association. For more info, see

Chicago Manual of Style

Patrick McGurrin and Christian Ross. "The Three R’s for Animal Treatment and Well-being". ASU - Ask A Biologist. 04 December, 2016.

MLA 2017 Style

Patrick McGurrin and Christian Ross. "The Three R’s for Animal Treatment and Well-being". ASU - Ask A Biologist. 04 Dec 2016. ASU - Ask A Biologist, Web. 12 Jun 2024.

Modern Language Association, 7th Ed. For more info, see

According to the rule of replacement, scientists should avoid using vertebrate animals, like fish or lizards. Instead, they should use invertebrate animals, like the C. elegans worm shown here.

Be Part of
Ask A Biologist

By volunteering, or simply sending us feedback on the site. Scientists, teachers, writers, illustrators, and translators are all important to the program. If you are interested in helping with the website we have a Volunteers page to get the process started.

Donate icon  Contribute

Share this page:


Share to Google Classroom