The Three Rs framework places Refinement at the centre of improving welfare for animals that continue to be used in scientific research.
Refinement represents the most immediately achievable of the Three Rs for improving the welfare of animals currently used in research. Even within existing regulatory frameworks, there is substantial room to reduce suffering through better housing, enrichment, social housing, anaesthesia, analgesia, and humane endpoints. Many refinements have been shown to improve not just animal welfare but also the quality and reproducibility of research data, as stressed animals produce noisier biological data. The welfare-science alignment is strong. However, implementation of known refinements remains inconsistent across institutions and countries, suggesting that awareness, training, and institutional culture are important barriers to welfare improvement in research settings.