Effect of perzinfotel and a proprietary phospholipase A2 inhibitor on kinetic gait and subjective lameness scores in dogs with sodium urate-induced synovitis

Objective—To investigate the ability of perzinfotel (an N-methyl-d-aspartate receptor antagonist) and a proprietary phospholipase A2 (PLA2) inhibitor to attenuate lameness in dogs with sodium urate (SU)–induced synovitis. Animals—8 adult dogs. Procedures—A blinded 4-way crossover study was performed. Dogs received perzinfotel (10 mg/kg), a proprietary PLA2 inhibitor (10 mg/kg), carprofen (4.4 mg/kg; positive control treatment), or no treatment (negative control treatment). On the fourth day after initiation of treatment, synovitis was induced via intra-articular injection of SU 1 hour before administration of the last treatment dose. Ground reaction forces were measured and clinical lameness evaluations were performed before (baseline [time 0]) and 2, 4, 6, 8, 12, and 25 hours after SU injection. There was a 21-day washout period between subsequent treatments. Data were analyzed via repeated-measures ANOVAs. Results—Peak vertical force (PVF) and vertical impulse (VI) values for negative control and perzinfotel treatments were significantly lower at 2 and 4 hours, compared with baseline values. Values for PVF and VI for the PLA2 inhibitor and positive control treatments did not differ from baseline values at any time points. Between-treatment comparisons revealed significantly higher PVF and VI values for the positive control treatment than for the negative control and perzinfotel treatments at 2 and 4 hours. Values for VI were higher for PLA2 inhibitor treatment than for negative control treatment at 2 hours. Conclusions and Clinical Relevance—Perzinfotel did not significantly alter SU–induced lameness. The proprietary PLA2 inhibitor attenuated lameness but not as completely as did carprofen.