Objective Osteoarthritis (OA) is the most common joint disorder in humans and dogs. Due to its chronic progressive nature, the predominant clinical signs after a certain point are pain and immobility. The similar pathogenesis allows conclusions to be drawn from canine to human OA. Current treatments are limited and often attempt to treat OA symptoms rather than improve joint structure and function. Collagen hydrolysates as oral supplements are a promising therapeutic option to achieve this advanced therapeutic aim in both species. The effects of oral supplementation were therefore investigated in canine OA patients. Method In a systematic, placebo-controlled, double-blind interventional study in 31 dogs with naturally occurring OA, the efficacy of oral supplementation of specific bioactive collagen peptides (BCP) was tested in comparison to the approved combination of the active substances omega-3 fatty acids and vitamin E. The dogs were examined on a horizontal treadmill with 4 integrated piezoelectric force plates at the beginning and end of a twelve-week test period. At both points, the owners completed a specific questionnaire containing the validated Canine Brief Pain Inventory (CBPI) and the dogs were fitted with accelerometers to record total daily activity data. Results Only the oral supplementation of BCP resulted in a significant improvement of several kinetic parameters measured using a force-plate fitted treadmill, and the quality of life assessed by CBPI, while accelerometry was unaffected by the intervention. Conclusion The results of this three-month BCP supplementation study using objective measurement parameters in dogs with naturally occurring OA demonstrate an efficacy, suggesting the therapeutic use of BCP in canine OA patients and demonstrating the relevance of this collagen hydrolysate formulation for the treatment of OA in human patients as well.