For those of you feeding food and supplements with glucosamine, check this link to make sure they are getting enough.
http://www.walkervalleyvet.com/otc-meds.htm
None of the foods and/or supplements I know of have enough to be beneficial.
I was giving Lady Nupro Joint support formula when my vet pointed that out to me. At eight pounds, Lady needs 300 mg of glucosamine per day. It didn't have enough so she had me add Glycoflex. Cosequin is another great one.