The effects of epidural deracoxib on the ground reaction forces in an acute stifle synovitis model

Objective— To evaluate the efficacy of epidurally administered deracoxib to mediate the signs of a sodium urate crystal-induced stifle synovitis in dogs, and to compare the efficacy of epidural versus subcutaneously administered deracoxib. Study Design— Experimental, randomized, blinded, placebo-controlled modified cross-over design. Animals— Random source, adult, mixed breed dogs (n=24; 14 males, 10 females). Methods— Sodium urate crystals were used to create a stifle synovitis model to evaluate the efficacy of deracoxib. Dogs were divided into 4 groups: 3 mg/kg epidural deracoxib, 1.5 mg/kg epidural deracoxib, 3 mg/kg subcutaneous deracoxib, and a placebo (vehicle for deracoxib). Force plate and subjective evaluations were made at time 0, 2, 4, 8, 12, and 24 hours post-treatment. Repeated measures ANOVA with Bonferroni-corrected post hoc comparisons was used to determine significant treatment effects. Results— Peak vertical force (PVF) and vertical impulse (VI) were both significantly higher in deracoxib treated dogs compared with placebo. For 3 mg/kg epidural and subcutaneous deracoxib, PVF and VI were significantly greater than for 1.5 mg/kg epidural deracoxib. Overall pain score for all deracoxib-treated dogs was significantly lower than for placebo dogs. Conclusions— Epidural administration of deracoxib is effective at providing analgesia in an acute joint pain model; however, it does not appear to be more effective than systemic administration. Clinical Relevance— Injectable deracoxib is effective in providing analgesia in acute inflammatory conditions of synovial joints.