[sunshine D]

A C. The difference is the added msm & heres info on msm
MSM (methylsulfonylmethane) is a form of sulphur which can be valuable for arthritis, joint pain and swellings. It can be particularly beneficial for acute muscle injuries and some forms of arthritis as it strengthens connective tissue and also helps to increase the permeability of the joint and muscle membranes allowing the release of excess fluid. This can result in a relief of swelling as well as drainage of inflammatory toxins. However, many dogs are sensitive or intolerant to sulphur compounds which can then result in fatigue, shortness of breath, congestion, immune issues, or skin problems. In addition, the long-term use of MSM depletes calcium levels which then exacerbates joint problems. All of these symptoms can occur shortly after taking the supplement or appear more slowly over time. No matter how your dog responds, dose on the side of caution and limit the use of MSM to thirty days unless obvious benefit is demonstrated beyond that time.