Refining In-Cage Enrichment for Specialized Mouse Scenarios

Environmental enrichment is a critical component of a high-quality animal care and use program to provide opportunities for species-specific behaviors and redirect abnormal repetitive behaviors. We used a scoring system to review our enrichment for singly housed mice to assess usage of supplied items. Following the confirmation of utilization of the selected enrichment, we applied the scoring system to address 2 cases of abnormal behavior. Repetitive food shredding in CD-1 mice was reduced by both manzanita sticks and running wheels; however, manzanita sticks were selected for operational ease. Focal auricular trauma associated with ear tags in BALB/c mice was decreased when gnawing items were provided, thus slowing the deterioration of ear tag condition. Scoring for all 3 studies focused on use of the enrichment, incorporation into the nest, or reduction of abnormal repetitive behavior. The development of a scoring system permits the objective assessment and selection of enrichment for unique scenarios, thus enhancing animal welfare and permitting a standardized way to evaluate enrichment for specialized projects.