George, A. J., Harmsen, B. J., Ford, J. A. et al. 2023. Evaluation of submental blood collection in mice (Mus musculus). JAALAS 62(1), 92–98.

The submental route is an option for nonterminal and serial blood collection in mice. This study compared the submental route to the maxillary route (also referred to as the submandibular route). The study used male CD1 and C57BL/6 strains of mice in 2 age groups: 8 and 19 wk. To simulate repeated toxicokinetic blood collection, blood was collected from each mouse at 1 and 24-h on Study Day 1, and at 1, 4 and 24 h on Study Day 16. Food consumption, body weights, and clinical observations were assessed daily. No apparent differences were found between the 2 blood collection sites in terms of either food consumption or body weight. Mice bled via the submental route showed fewer adverse clinical effects than did mice bled via the maxillary route. Clinical pathology showed no differences between the 2 methods. In addition, 7 trained technicians, who were inexperienced with the 2 bleeding methods prior to these evaluations, were surveyed to gain insights into expectations and overall experience of using the 2 routes. All 7 technicians preferred the submental route to the maxillary route. Furthermore, the average time needed to become proficient in submental blood collection (1.6 d) was less than that required to become proficient in maxillary blood collection (2.6 d). The qualitative aspects of this study, combined with fewer adverse clinical events, suggest ways to improve both animal and staff welfare. Our findings suggest that the submental route is safe, effective, and easier than the maxillary route for nonterminal serial blood collection in mice.