Laboratory rodents are the most numerous research animals globally, and evidence increasingly shows that standard housing practices impair both welfare and research reliability.
Laboratory rodent welfare affects both the animals and the science they generate. Chronically stressed mice and rats show elevated corticosterone, altered immune function, and behavioral abnormalities that introduce bias into research results. Better welfare — through enriched housing, social grouping, and handling training — simultaneously reduces animal suffering and improves data reliability. The interests of the animal and the science converge strongly in laboratory rodent welfare improvement.