Robenacoxib versus meloxicam for the management of pain and inflammation associated with soft tissue surgery in dogs: a randomized, non-inferiority clinical trial

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are used routinely to control pain and inflammation after surgery in dogs. Robenacoxib is a new NSAID with high selectivity for the cyclo-oxygenase (COX)-2 isoform of COX. The objective of this study was to evaluate the efficacy and tolerability of robenacoxib for the management of peri-operative pain and inflammation associated with soft tissue surgery in dogs. The study was a prospective, randomized, blinded, positive-controlled, non-inferiority, multi-center clinical trial. A total of 174 dogs undergoing major soft tissue surgery were included and randomly allocated in a 2: 1 ratio to receive either robenacoxib (n = 118) or the positive control, meloxicam (n = 56). Each dog received an initial dose subcutaneously prior to surgery (robenacoxib 2 mg/kg, meloxicam 0.2 mg/kg), followed by daily oral doses (robenacoxib 1-2 mg/kg, meloxicam 0.1 mg/kg) for 12 days (range 10-14) after surgery. Pain and inflammation were assessed subjectively using the Glasgow Composite Pain Scale (GCPS) by clinicians as the primary end point and additional evaluations by the clinicians and animal owners as secondary endpoints. Results: Both treatments provided similar pain control, with no significant differences between groups for any efficacy variable using non-parametric analyses (Mann-Whitney U test). In no dog was analgesic rescue therapy administered. Non-inferior efficacy of robenacoxib compared to meloxicam was demonstrated statistically for the primary and all secondary endpoints using parametric analysis of variance, although the data were not normally distributed even after log transformation. For the primary endpoint (reciprocal of the modified GCPS score), the relative efficacy of robenacoxib/meloxicam was 1.12 with a 95% confidence interval of 0.97-1.29. Both treatments were well tolerated and did not affect buccal mucosal bleeding time. Conclusion: A treatment regimen of robenacoxib by subcutaneous injection followed by oral tablets had good tolerability and non-inferior efficacy compared to meloxicam for the management of peri-operative pain and inflammation associated with soft tissue surgery in dogs.