Rodent welfare in research extends well beyond survival to encompass positive affective states, social needs, and species-appropriate environmental complexity.
Rodent welfare in research has historically focused primarily on survival and the avoidance of obvious suffering — meeting housing minimums and conducting procedures within regulatory frameworks. Modern rodent welfare science recognises that this is insufficient: social isolation causes welfare harm; barren environments frustrate natural behaviour; positive affective states are measurable and relevant to welfare assessment. The recognition that stressed, bored laboratory rodents show increased experimental variability also aligns welfare improvement with scientific quality — better welfare produces more reliable data. Advances including validated pain assessment using grimace scales, positive handling protocols that reduce anxiety, and social housing requirements that match species needs are transforming rodent welfare in research facilities committed to genuine refinement. The challenge is embedding these advances consistently across institutions rather than limiting them to leading centres.