MSM Methylsulfonylmethane MSM is another naturally occurring substance that is regularly combined with both glucosamine and chondroitin in joint supplements for senior cats and dogs.
Glucosamine and Chondroitin Supplements for Arthritis
The variability in chondroitin sulfate composition extends to its origin, making it possible to differentiate between chondroitin sulfate from terrestrial and marine sources.