This double blinded, placebo- controlled randomised trial compared a control diet with one enriched with omega- 3 fatty acids from fish oil in dogs affected with osteoarthritis. 30 client- owned dogs diagnosed with stifle or hip osteoarthritis were fed either diet for a 13 week period and were scored by their owners on their ability to perform normal everyday tasks. They also had force plate analysis performed at baseline and throughout the study period. Results showed that feeding a diet high in omega- 3 fatty acids from fish oil resulted in improved locomotion and better ability in the activities of daily living compared to dogs fed the control diet.