Glucosamine Sulphate is fundamental in all connective tissue manufacture and acknowledged by many to be helpful in maintaining mobility. It's an amino sugar formed from glucose and the amino acid glutamine and is normally made by the digestive process.
It appears that as some animals age, like humans, they do not manufacture enough glycosaminoglycans and protein.
Supplementation with orally administered Glucosamine Sulphate has been shown to be very beneficial.