Animal Experimentation: Alternatives to the Use of Animals in Research

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The majority of researchers, governments, and scientific regulatory bodies agree that when animals are used in research, their suffering should be minimized whenever possible. In addition, most also agree that the development of alternatives to animal testing is an important priority.

The Three Rs

In 1959 two scientists, zoologist William Russell and microbiologist Rex Burch, described three guiding principles which, for many researchers, still serve as a basis for the design of any experiments which involve the use of animals.

  • Reduce, whenever possible, the number of animals used in a given experiment.
  • Refine scientific and experimental methods to minimize pain, suffering, and distress, and to enhance the welfare of any experimental animals.
  • Replace experiments using animals with other types of experiments which do not use animals, whenever it is possible to achieve the same aims by doing so.

Alternatives to Animals

Currently there are two main alternatives which may be used in place of animals: in vitro and in silico experiments. In vitro experiments typically involve the use of cell cultures, while the term in silico refers to the use of computer models which simulate chemical, molecular, and cellular interactions. However both of these methods, while applicable in some situations, do have their limitations.

The most pressing argument against the use of in vitro and in silico techniques is that they simply cannot accurately reproduce the conditions found in a living animal, due to the enormous complexity of even the simplest forms of life. The problem is compounded when environmental factors are included – in vitro experiments cannot account for them, and in silico experiments cannot always accurately predict them.

In short, alternatives do exist, and they do work for certain applications – but these alternatives are not always appropriate.

Despite the problems with these alternatives, there have been some successes. Monoclonal antibodies, for example, could once be produced only in life animals, and the process often caused pain and distress. New techniques were developed which allow for the production of monoclonal antibodies in tissue culture, reducing the need for animal “antibody farms.”

Some types of animal testing are particularly difficult to replace. One of these is toxicological testing, due to the need to be able to explore all the possible effects of a drug on a living organism.

Recently, however, a practice called micro-dosing has been explored, with the hope that the practice might reduce the need for experimental animals in toxicology tests for human pharmaceuticals.

Micro-dosing involves the use of human volunteers, who receive a tiny dose of a given drug. The dose is far below that which would be expected to produce toxic effects, but is high enough that the drug will have an effect at the cellular level. There is virtually no risk to the drug recipient, and fewer animals are used because non-viable drugs are ruled out before any animal testing begins (whereas without micro-dosing, animal trials might go through several phases before a potential drug is found to be ineffective).

This post is part of the series: Animal Experimentation

A six-part series which examines practical and ethical issues involved in the use of animals for scientific research.

  1. An Introduction to the Use of Animal Experimentation in Medical Science
  2. A History of How Scientists Used Animal Testing to Make Medical Advances
  3. Animal Experimentation: Uses of Animals in Research
  4. Animal Experimentation: Practical and Ethical Issues
  5. Animal Experimentation: Alternatives to the Use of Animals in Research
  6. Animal Experimentation: Regulations for the Use of Animals in Research