Laboratory Rodent Welfare: Refinement and the 3Rs

Mice and rats used in research constitute the vast majority of laboratory animals globally; welfare refinement through housing, handling, and procedure improvements makes a significant difference to millions of animals.

Key Facts

Mice and rats account for over 80% of all laboratory animals used globally
Group housing significantly reduces stress hormones in laboratory rodents compared to isolation
Tunnel handling reduces fear and stress compared to tail handling in mice
Enriched housing with nesting material and hiding places improves welfare and data quality
Analgesic use after procedures is still inconsistently applied in many facilities

Welfare Considerations

Laboratory rodents experience chronic stress from inadequate housing, inappropriate social conditions, and repeated handling. Tail handling induces fear and struggling in mice compared to tunnel or cup handling. Group housing meets social needs but requires careful management to prevent aggression. Nesting material is a fundamental welfare requirement for thermoregulation in mice. Analgesia after surgery is underused due to concerns about confounding — but unmanaged pain itself confounds data and causes welfare harm.

What You Can Do

Support NC3Rs research into laboratory animal welfare refinement
Advocate for mandatory tunnel handling and group housing in rodent research guidelines
Engage with institutional animal care and use committees on refinement standards
Support research demonstrating that welfare improvements enhance data quality
Encourage veterinary oversight of analgesic protocols in research institutions