Evaluation of Analgesia Efficacy in Postoperative Mice Using Novel Cage-Side Measures

The ability to rapidly and accurately identify pain in mice is critical for providing them optimal care and welfare. To meet this need, we developed and validated the Grooming Transfer Test (GTT) and Nest Consolidation Test (NCT). We assessed these novel tests along with electronic von Frey and ambulatory parameters at baseline, after isoflurane anesthesia +/- analgesia, and after laparotomy in adult CD1 and C57BL/6 mice of both sexes, housed singly with or without an existing nest or in pairs. While ambulatory parameters had no and von Frey responses minimal significant changes after surgery, GTT and NCT were significantly altered for 48 hours after surgery in both sexes, strains, and across the various housing conditions. Buprenorphine and carprofen each reduced post-operative pain, however only the combination of the two completely prevented delays in nesting behavior. Therefore, these two novel cage-side methods can be used to quickly and objectively identify mice from a variety of signalments and housing conditions with alleviated and unalleviated postoperative pain.