How environmental enrichment for laboratory mice improves welfare and research quality simultaneously.
Laboratory mouse welfare has a dual benefit structure: improving the lives of research animals simultaneously improves research quality. Chronically stressed mice have elevated cortisol, altered immune function, and physiological variability that confounds experimental results. Enriched environments that allow mice to construct nests, hide, and engage in exploratory behavior produce animals with more stable baseline physiology and more reliable experimental responses. This means that investment in mouse welfare is investment in research quality — the two are not in tension. Regulatory frameworks in most jurisdictions now require enrichment provision for laboratory rodents, but the level of implementation varies significantly between institutions.