Laboratory Mouse Welfare Refinement

Mice are by far the most commonly used laboratory animals, making welfare refinement a high-impact priority.

Key Facts

Approximately 100 million mice are used in biomedical research globally each year
Mice have complex social needs and suffer in individual housing that is standard in many facilities
Environmental enrichment including nesting material, shelters, and social housing improves welfare significantly
Standard handling by tail-picking causes aversion and stress — tunnel handling reduces this substantially
Many welfare refinements improve both animal welfare and scientific reproducibility simultaneously

Welfare Considerations

Laboratory mouse welfare improvements offer some of the highest welfare impact per intervention of any area in animal welfare science, given the enormous numbers of animals involved. Simple, inexpensive refinements — providing nesting material, group housing, tunnel handling, and environmental enrichment — dramatically reduce stress responses and improve welfare with minimal effect on research validity. In many cases, reduced stress improves data consistency and reproducibility, creating aligned incentives for welfare improvement. Systematic application of the 3Rs — replacement, reduction, and refinement — across global mouse research could prevent enormous amounts of unnecessary suffering.

What You Can Do

Support implementation of the 3Rs framework at research institutions
Advocate for nesting material and social housing as minimum standards for laboratory mice
Donate to organizations developing and disseminating animal research refinement resources
Support funding for development of non-animal research alternatives
Ask research institutions about their animal welfare committee activities and policies