When choosing a supplement to provide glucosamine for dogs, look for one that provides the nutrient in the form of glucosamine sulfate or HCL as these are higher quality and more potent formulations. Dosages should be administered only in the appropriate amounts which will depend greatly on the age, size and health of the dog. Powder and liquid forms are usually more easily dispensed than pill forms. The beneficial results of glucosamine should become evident after just a couple weeks of regular use in normal cases and in about a month in more severe cases. Glucosamine is easily absorbed by the body and distributed to joint tissues without the negative side effects often produced by many drugs.