Assessment of Postoperative Analgesic Efficacy and Animal Well-Being Using a Novel Triaxial Accelerometer Device, the Rodent Fitbit-Like Telemetry Device

Accurate postoperative pain management is crucial for good animal welfare and science. We sought to evaluate mouse postoperative pain management efficacy by measuring activity using a novel triaxial acceleration device—the Rodent Fitbit-like telemetry device (RFB)—to monitor home cage activity. To determine if analgesics impacted activity levels, we evaluated activity in C57BL/6 male and female mice ( n = 6) that were attached with the RFB and administered EthiqaXR (XR; 3.25 mg/kg), meloxicam sustained release (MSR; 6 mg/kg), combined XR/MSR, or bupivacaine (5 mg/mL) compared with control mice provided sterile saline (5 mL/kg) subcutaneously. Activity in XR/MSR and XR-treated mice was significantly increased on night 0 (N0) but only trended downward from N2 to N4 compared with baseline. No significant changes in activity were detected after administration of MSR, bupivacaine, and saline. We examined the effective analgesic period of XR, MSR, XR/MSR, and bupivacaine based on electric von Frey and the RFB using a hind paw incision pain model in C57BL/6 male ( n = 8) and female mice ( n = 7) attached with the RFB. Preoperative XR and XR/MSR mice had reduced pain based on von Frey with no reduction in activity based on the RFB compared with other treatment groups. Only mice provided saline demonstrated a significant decrease in activity on N0, suggesting limited duration of spontaneous pain elicited from the minor pain model. In summary, activity was an effective and sensitive indicator for detecting pain using a paw incision pain model in C57BL/6 mice within the first 24 h postsurgery. Additional studies using a major operative procedure should be performed to determine the effectiveness of activity as a pain detection indicator.