Research shows that frequent cage changes elicit increased locomotor activity, disrupt sleep patterns, and elevate anxiety and stress levels in mice, thereby introducing potential confounding variables in experimental outcomes.
Following tests and observations conducted by the Animal Facility Working Group, it has been found that extending the interval between cage changes leads to positive outcomes in improved breeding performance, increased pup survival, and reduction in disturbances and aggression among mice. 

In alignment with the 3R principles (Replacement, Reduction, and Refinement), and to promote both enhanced animal welfare and greater scientific validity, cage change intervals will henceforth, starting from May 2025, be adjusted according to the number of animals housed per cage. Depending on group size and cage type, intervals will vary from one to four weeks. Specific guidelines for each cage type and animal number are detailed in the accompanying table.

Researchers are advised to review these updated practices and integrate them into study planning where applicable. For any inquiries or concerns related to ongoing or future studies, please consult with the assigned animal technician to align cage change procedures.

Cage Change Intervals: