How does research affect animal welfare?

• The impact of research on animals varies from almost insignificant effects to major effects on some that undergo very painful or distressing procedures.
• The welfare of animals may also be affected if their housing and husbandry does not meet their needs.
• In some cases harm may be caused as an unintended consequence of the research (for instance, the pain of an injection or surgery where the objective was to place a sensor to monitor some biological function).