by: Kristin Bailey, DVM (Practice Limited to Surgery)
Nutraceutical supplementation has become commonplace for the management of osteoarthritis in dogs. The most frequently prescribed supplements include glucosamine sulfate or hydrochloride, chondroitin sulfate, and essential fatty acids.
After oral administration, glucosamine has been shown to diffuse into articular tissues and appears to be utilized by chondrocytes to produce glycosaminoglycans, the building blocks for all connective tissues including cartilage. Less is known about the distribution of chondroitin sulfate when administered orally, but in vitro it may reduce destructive enzymes in joint fluid and cartilage, among other things. Appropriate studies are lacking in regard to the efficacy and outcome of glucosamine and chondroitin administration in dogs with OA. Glucosamine appears to be more beneficial than chondroitin, but there is no solid evidence that use of these products alone or together improves clinical outcome. Combined glucosamine/chondroitin supplements are generally safe to administer with minimal negative consequences. n-3 essential fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to reduce formation of inflammatory mediators responsible for articular cartilage breakdown. Studies have documented clinical improvement in dogs with OA on omega-3 supplementation. These particular EFAs are derived from fish oils and can be administered as a capsule, liquid, or in a commercial diet. In short, current evidence supports the use of EFAs over glucosamine/chondroitin sulfate in patients with OA, but further studies are needed.