Unrecognized and untreated pain in laboratory animals compromises both welfare and research quality, and advances in pain recognition tools are improving but not yet universally implemented.
Pain in laboratory animals has historically been under-recognized because animals cannot verbally report discomfort and because research culture has sometimes minimized welfare concerns. The development of validated grimace scales has transformed pain assessment by providing objective, reproducible tools for non-verbal species. Implementation, however, lags behind validation. Many facilities lack systematic post-operative pain monitoring, relying on subjective impressions rather than validated scores. Improved pain recognition and treatment benefits animals directly and improves research quality by reducing confounding physiological stress responses.