All research involving animals must adhere to “The 3R's"
Reduction: This involves using fewer animals to obtain the same (or more) information from a research study. Good experimental design and advanced statistical analysis make certain that researchers use the optimal number of animals. Improved scanning techniques allow researchers to non-invasively study tumors and collect more data from the same animal.
Refinement: This involves improving animal welfare and improving procedures so that they do not cause unnecessary distress or pain to the animals. This also involves keeping the animals in living conditions that are appropriate for their species, and providing the animals with environmental enrichment to ensure the overall well-being of the animals.
Replacement: Whenever possible, the use of animals must be replaced with non-animal methods such as computer models, cell and tissue cultures, and epidemiological studies. Statistical data (data already obtained from animal research) can help replace the need for more animals. Many safety tests can be done without using animals. For example, the Ames test (a biological assay to assess the mutagenic potential of chemical compounds) can be tested in bacteria instead of rodents in order to see if the chemical will likely damage DNA or if it has the potential to cause cancer.
More information can be found on the website of The National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs).