Mice are the most commonly used laboratory animals globally, and applying the 3Rs framework rigorously can significantly reduce suffering while maintaining scientific validity.
Laboratory mice are sentient beings whose welfare is often underestimated due to their small size and status as research tools. Evidence from multiple research programs demonstrates that mice experience fear, pain, and stress, and that these experiences affect their physiology in ways that can confound research results as well as causing suffering. Applying the 3Rs comprehensively — replacing animal models with alternatives where possible, reducing numbers through better experimental design, and refining procedures to minimise pain and distress — is both an ethical imperative and increasingly understood as scientifically beneficial. Simple refinements like providing nesting material, using non-aversive handling methods like tunnel handling, and ensuring adequate analgesia can dramatically improve welfare with minimal cost.