Collagen hydrolysates for dogs with osteoarthritis: Bringing a food myth from bowl to the bench and back

Abstract

Osteoarthritis (OA) is a common joint disease in dogs that involves long-term inflammation, breakdown of cartilage, and pain. Treatment mainly focuses on reducing symptoms through medication, changes in activity, and nutrition. Collagen hydrolysate (CH) is considered a potentially interesting nutritional supplement for OA, but there is still limited strong scientific evidence for its effectiveness. This thesis investigated how CH is absorbed in the body, how it may work, and whether it has a clinical effect in dogs with OA. CH was rapidly absorbed in dogs at doses above 250 mg/kg, similar to what has been observed in humans. In laboratory studies using cartilage and joint cells, CH-enriched serum reduced the production of certain inflammatory mediators (such as CXCL10, CCL2, and GM-CSF). This effect is likely related to inhibition of the IFN/JAK/STAT signaling pathway. This suggests that CH may influence the interaction between joint tissues and the immune system, which plays an important role in OA. Because classical inflammation models may not accurately reflect the situation in real joints, alternative models were also tested. Some standard cytokine-based models showed little response to anti-inflammatory treatment, while a model that more closely resembles the natural disease showed a clearer response to treatment. In a clinical study in dogs with OA, no significant difference was found between dogs receiving CH and those receiving a placebo after 12 weeks. However, both groups showed slight improvement. This indicates that CH did not have a clear clinical effect in this study. Still, the laboratory findings suggest that there may be specific subgroups of patients in which CH could be relevant. Overall, these results provide more insight into CH, but do not yet offer sufficient evidence for broad clinical use.