Laboratory Mouse Welfare — the Most Used Research Animal

Mice account for approximately 60% of all laboratory animals globally, yet their welfare receives less public attention than that of primates or larger animals.

Key Facts

Approximately 60 million mice are used in biomedical research globally each year
Standard laboratory housing in small plastic boxes prevents burrowing and nesting
Mice have been shown to display empathy — showing distress when seeing other mice in pain
Environmental enrichment significantly reduces stress and improves research reproducibility
Many pain and stress studies have been conducted on male mice only, limiting translational value

Welfare Considerations

Laboratory mouse welfare has improved substantially over decades — nesting material, enrichment, and group housing are now widely provided. However, significant welfare gaps remain: isolation housing for experimental purposes, procedures conducted without analgesia, and the scale of animals used in repeated experiments. Crucially, poor welfare conditions reduce reproducibility and translatability of research — making mouse welfare a scientific concern as well as an ethical one. The 3Rs framework (Replace, Reduce, Refine) has driven progress but implementation remains uneven.

What You Can Do

Support NC3Rs (National Centre for the 3Rs) and similar research replacement organizations
Advocate for analgesia requirements in mouse experimental protocols
Support funding for organ-on-a-chip and other replacement technologies
Encourage your institution to publish detailed 3Rs implementation reports
Choose cosmetic and household product brands that do not test on animals