Hi. Supplements to a dog's diet such as Glucosamine and Chondroitin Sulfate, Omega Fatty Acids, Vitamin E, Selenium, and MSM (Methylsulfonylmethane) all assist in decreasing inflammation and improving the body's ability to repair and strengthen tissues. Supplements, however, will not reverse structural changes in a joint such as torn cartilage, calcium deposits and advanced scar tissue.