Glucosamine suphate is an amino sugar formed from glucose and the amino acid glutamine. Normally made by the digestive process, Glucosamine Sulphate is fundamental in all connective tissue manufacture. Connective tissue or collagen is rich in protoglycans, which are made up of glycosaminoglycans (GAGs) and protein. Glucosamine Sulphate is the main precursor in GAG production.
It appears that as some animals age, like humans, they do not manufacture enough GAG, one of the major causes of joint stiffness. Supplementation with orally administered Glucosamine Sulphate has been shown to be very beneficial for joint support.
Suggested additions:
Non acidic vitamin C. Vitamin C is essential to cartilage integrity
B vitamins, especially Pantothenic Acid (B5) and Niacinamide (B3)
S-adenosylmethionine (SAM) is formed in the body by the amino acid methionine and adenosyl-triphosphate (ATP). SAM has been shown to be, like Glucosamine, essential to cartilage formation and joint integrity.
Herbs, including, Boswellia, Cats Claw, and Turmeric. have been shown to exert a notable anti-inflammatory effect upon joints, easing pain while Glucosamine starts to repair the joint.
Fish Oil, shown to be useful in supporting joint mobility. 
Topically, massage area with olive oil or any rubbing liniment which you find useful.
Gentle exercise is a must to keep joints mobile, but do not overdo it as too much can cause more pain.
 
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