A Summary of the Current Evidence for Joint Supplements in Dogs
We evaluated all of the common (and some of the uncommon) supplement ingredients marketed for joint health in dogs, and found some surprising results. There was a wide range in both evidence quality, quantity, and overall effectiveness within this category. Below are the winners:
Highest quality evidence and overall efficacy:
PetEvidenceProject grade: A
Multiple well-designed clinical trials with a low risk of bias consistently demonstrated an improvement in joint pain and mobility in dogs with arthritis. This was demonstrated to benefit dogs with both early and later stage arthritis with very low risk of side effects. Of note, only marine source omega-3 had the benefits seen, plant-source omega-3 (e.g. flaxseed) has low conversion to EPA and DHA in dogs.
Runner’s up:
PetEvidenceProject grade: B
Undenatured type II collagen (UC-II)
PetEvidenceProject grade: B
Both of these showed consistent benefit across multiple trials, though the evidence was not as robust as for omega-3’s. UC-II studies had slightly higher risk of bias, which pushed the grade slightly lower. It is unclear if using these in combination with omega-3 fish oil would provide an additive benefit, though combination use appeared to be safe, when evaluated.
Supplements that had poor showing in the literature may perhaps be the most surprising to pet owners:
PetEvidenceProject grade: D
These supplements consistently demonstrated a lack of benefit across multiple studies, despite their seemingly common use in many supplements. The placebo effect was documented in some studies, underscoring the importance of a placebo group and blinding in clinical trials. While multiple combination products include glucosamine and chondroitin as ingredients, one must wonder if these ingredients are helpful. For such combination products, the other ingredients are likely to be of greater benefit (if they are omega-3’s, GLM, or UC-II). However, glucosamine and chondroitin appeared safe with minimal reported adverse effects
Final Thoughts
While some joint supplements demonstrated a benefit to joint health in dogs, addressing joint disease requires more than just a supplement. Other evidence has shown that maintaining a lean body weight, consistent low-impact exercise, and veterinary guidance are all important factors for a holistic approach to joint health (and health in general). For more information, the following articles provide a more in-depth look into complete joint care for dogs
How to Improve Joint Health and Mobility in the Aging Dog
My Dog Has Arthritis: A Vet's Evidence-Based Guide to Pain Relief and Mobility
Evidence at a glance — all 7 reviewed supplements in joint support, sorted by evidence grade.