Therapeutic management of osteoarthritis (OA) can include substances that claim to possess benefits beyond those of daily nutrient needs. These substances include long-chain polyunsaturated omega-3 fatty acids; particularly, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study compared 2 groups of 15 dogs with OA: group 1 fed a veterinary therapeutic diet containing 1.08% EPA and DHA from fish origin and group 2 fed
a diet without omega-3. The dogs were evaluated by peak vertical force and case-specific outcome measures. Dogs were excluded if they had cranial cruciate ligature surgery within 1 year of the study, were receiving a natural health product (including omega-3) supplement 6 weeks before the study, or received an NSAID 4 weeks before the study. Dogs were also excluded if they were pregnant, had neurologic disease, had forelimb muscular atrophy, received corticosteroids, or received polysulfated glycosaminoglycans. Radiographs (of hips, elbows, and stifles) were obtained while the dogs were sedated.

Dogs eating the therapeutic diet were significantly less lame 7 weeks after initiation. The improvement in functional disability was maintained throughout the 13-week study. This effect was similar to reports of improved lameness after NSAID or powder of elk velvet antler administration. These data support high omega-3 supplementation in veterinary therapeutic diets as part of OA multimodal management. Study supported in part by a grant from Nestlé Purina PetCare Company

Commentary
Omega-3 fatty acid supplementation can treat lameness in dogs, but its administration can be problematic. First, a large amount must be administered to achieve therapeutic doses; this can create difficulty when administering capsules or, in cases of liquid, cause the patient not to eat. Fatty acid administration can also cause diarrhea and must be used cautiously in dogs with sensitive GI tracts or those receiving other potential diarrhea-causing agents (eg, NSAIDS, herbal medications). A diet enriched with fatty acids in antiinflammatory amounts has a shorter shelf life than conventional foods and may have to be thrown away before eaten. Calories from fatty acids should be counted when supplemented. Still, omega-3 should remain an integral part of a comprehensive multimodal pain management plan.—Heather Troyer, DVM, DABVP, CVA

Source
Effects of feeding a high omega-3 fatty acids diet in dogs with naturally occurring osteoarthritis. Moreau M, Troncy E, del Castillo JRE, et al. J ANIM PHYSIOL ANIM NUTR doi: 10.1111/j.1439-0396.2012.01325.x