Millions of animals are used in scientific research each year. The Three Rs framework — Replacement, Reduction, Refinement — guides efforts to improve welfare and reduce harm.
Research animal welfare sits at the intersection of scientific necessity and ethical obligation. Animals used in research experience varying degrees of pain, distress, and suffering — from minimally invasive blood sampling to severe surgical procedures or toxicity testing. The welfare cost of research use must be justified by the potential scientific and medical benefit, and minimised through rigorous application of the Three Rs. Refinement encompasses a wide range of practices: providing environmental enrichment that allows natural behaviour expression (crucial for validity of behavioural studies as well as welfare), using anaesthesia and analgesia appropriately, training animals to voluntarily participate in non-aversive procedures to reduce capture and handling stress, and implementing humane endpoints that end experiments before animals reach maximum suffering. Housing conditions for laboratory animals — particularly social housing for social species, and environmental complexity for cognitively complex species — have improved substantially but remain below natural conditions in most facilities. The push toward New Approach Methodologies (NAMs) including organoids, organ-on-chip systems, and AI-based toxicology prediction is creating genuine replacement opportunities that deserve substantial investment.