The objective of this study was to determine whether Tui-na massage in combination with conventional medication (CM) constitutes a more effective treatment for canine osteoarthritis than using CM alone. A total of 47 dogs with radiographic changes consistent with osteoarthritis and already on CM were enrolled in the study. The dogs were randomly assigned to either control (n=24) or experimental treatment groups (n=23). Dogs in the Treatment Group received a weekly Tui-na massage for five weeks, whereas those in the Control Group were seen twice, five weeks apart. All subjects continued their CM during the study. Outcome data included scores for range of motion (ROM), walking frequency/duration, quality of life (QoL), pain and weakness collected pre-trial and at study termination. Comparison between groups after five weeks demonstrated significantly greater improvement for the Treatment Group for all outcome data scores: ROM (p = 1.48×10^-10), numbers of walks per day (p = 0.015), total walking time per day (p = 2.75×10^-5), QoL (p = 1.43×10^-8), pain (p = 3.01×10^-10) and weakness (p = 1.63×10^-9). The study findings demonstrate that regular Tui-na treatment can serve as an effective coadjuvant in a multimodal treatment and offer statistically significant benefits for dogs suffering from OA.