Effects of intra-articular botulinum toxin type A (Botox) in dogs with chronic osteoarthritis.

OBJECTIVES To evaluate the effects of intra-articular botulinum neurotoxin type A (BoNT/A) in dogs with chronic osteo- arthritis. METHODS Client-owned dogs with lameness and discomfort attributed to unilateral elbow or hip osteoarthritis were eligible for inclusion (n = 5). All dogs had BoNT/A (25 units) administered to the affected joint (2 elbows, 3 hips). Dogs were evaluated by pressure platform gait analysis before and at two, four, eight, and 12 weeks post-injection, and by client perception of outcome. RESULTS In experimental limbs, ground reaction forces (peak vertical force and vertical impulse) consistently improved for a variable period of time following intra-articular BoNT/A therapy. These changes were not, however, observed in the contralateral limbs, in which values remained relatively unchanged or decreased. Four out of five owners reported at least some improvement in their dog's condition following treatment. CLINICAL SIGNIFICANCE A multimodal approach with the intra-articular administration of BoNT/A may be an option for osteoarthritis patients that are unresponsive to medical management and unable to undergo surgery. However, the findings of this study are preliminary and must be verified by further investigation.