Placebo-controlled randomized clinical study using a collagen hydrolysate-enriched diet in dogs with osteoarthritis

Osteoarthritis (OA) is a prevalent cause of chronic pain in dogs. Previous clinical studies suggest potential benefits of collagen hydrolysate (CH) supplementation, yet limitations in patient selection and study design have hindered definitive conclusions. This randomized, double-blind, placebo-controlled study evaluated the efficacy of a CH-enriched diet compared to an isocaloric placebo diet over 12 weeks in dogs with radiographically confirmed OA and mild clinical signs. Clinical efficacy was assessed at weeks 0, 3, 6, 9, and 12 using client-reported outcome measures, including the Liverpool OsteoArthritis in Dogs (LOAD) and Canine Brief Pain Inventory (CBPI) questionnaires, alongside kinetic gait analysis using a force-plate at weeks 0, 6, and 12. The primary endpoint was the difference in baseline-corrected LOAD scores between the CH and placebo diet at week 12. Forty-five dogs enrolled; nine discontinued, with three dropouts related to osteoarthritis severity or the provided food. Rescue analgesia was equally used both groups (CH: 5/17 dogs and Placebo: 4/19 dogs). Complete-case analysis revealed no differences between groups for LOAD, CBPI scores, or gait analysis. Both groups showed improvement, indicating a caregiver placebo effect. These results indicate no short-term benefit of CH on the assessed clinical and objective outcomes, potentially due to the relatively small and heterogeneous cohort and limited study duration. Further studies with larger populations, longer follow-up, and patient stratification are warranted.