Efficacy of ABT-116, an antagonist of transient receptor potential vanilloid type 1, in providing analgesia for dogs with chemically induced synovitis.

OBJECTIVE: To investigate the ability of ABT-116 (a proprietary antagonist of transient receptor potential vanilloid type 1) administered at 2 doses to attenuate lameness in dogs with experimentally induced urate synovitis. ANIMALS: 8 purpose-bred mixed-breed dogs. PROCEDURES: In a 4-way crossover study, dogs orally received each of low-dose ABT-116 treatment (LDA; 10 mg/kg), high-dose ABT-116 treatment (HDA; 30 mg/kg), firocoxib (5 mg/kg), and no treatment (nontreatment) once a day for 2 days, in a randomly assigned order. Synovitis was induced on the second day of each treatment period by intra-articular injection of either stifle joint with sodium urate, alternating between joints for each treatment period, beginning with the left stifle joint. Ground reaction forces, clinical lameness scores, and rectal temperature were assessed before the injection (baseline) and at various points afterward. RESULTS: Lameness scores at the 2-, 6-, and 12-hour assessment points were higher than baseline scores for HDA and nontreatment, whereas scores at the 2- and 6-hour points were higher than baseline scores for LDA. For firocoxib, there was no difference from baseline scores in lameness scores at any point. Compared with baseline values, peak vertical force and vertical impulse were lower at 2 and 6 hours for HDA and nontreatment and at 2 hours for LDA. No changes in these values were evident for firocoxib. The HDA or LDA resulted in higher rectal temperatures than did treatment with firocoxib or nothing, but those temperatures did not differ among treatments. CONCLUSIONS AND CLINICAL RELEVANCE: HDA had no apparent effect on sodium urate-induced lameness; LDA did attenuate the lameness but not as completely as firocoxib treatment. High rectal temperature is an adverse effect of oral ABT-116 administration that may be of clinical concern.

Evaluation of pentosan polysulfate sodium in the postoperative recovery from cranial cruciate injury in dogs: a randomized, placebo-controlled clinical trial.

OBJECTIVE: To evaluate the efficacy of pentosan polysulfate (PPS) for improving the recovery period and mitigate the progression of osteoarthritis (OA) of the canine stifle after extracapsular stabilization of cranial cruciate ligament (CCL) injuries. STUDY DESIGN: Randomized, blinded, placebo-controlled clinical trial. ANIMALS: Dogs (n=40) with unilateral CCL instability. METHODS: Each dog had an extracapsular stabilization of the stifle with or without partial meniscectomy. Dogs were divided into 4 groups based on preoperative radiographic assessment and whether a partial meniscectomy was performed. Dogs were randomly assigned to either (3 mg/kg) PPS or placebo treatment in each group, and then injected subcutaneously weekly for 4 weeks. Lameness, radiographic changes, biological marker concentration in blood and urine, and ground reaction forces (GRFs) were collected preoperatively, and at 6, 12, 24, and 48 weeks. Data were analyzed within and between groups using repeated measures ANOVA; P<.05 was considered significant. RESULTS: No adverse reactions to PPS were reported. Thirty-nine dogs completed a minimum of 24-weeks follow-up and 33 dogs completed 48 weeks. All dogs clinically improved after surgery without differences in lameness score, vertical GRFs, or radiographic progression. Grouped and evaluated only by initial radiographic score, PPS-treated dogs improved significantly faster in braking GRFs than placebo-treated dogs. In dogs with partial meniscectomies, urine deoxypyridinoline, and serum carboxy-propeptide of type II collagen were significantly increased at 6 weeks in placebo-treated dogs compared with PPS-treated dogs. CONCLUSIONS: PPS administered after stabilization of the cruciate deficient stifle may prove to be a useful adjunctive treatment option, although further studies are necessary to substantiate this claim.