Efficacy of Glucosamine and Chondroitin

Question
Hello - I am curious about the efficacy of glucosamine and chondroitin in
older dogs.  I have a ten year old pitbull with an arthritic paw and who
recently injured his cruciate. I've been giving him 2/3 oz. combination liquid
glucosamine Hcl 99% (1600 mg per oz.), chondroitin sulfate(1200 mg per
oz.), MSM (1000 mg per oz.), manganese (7 mg per oz.).  His cruciate is
healing very well with an occasional limp, his arthritic paw (left front)  causes
a bit of a limp.  He is a relatively active 10 year old (plays daily with 3 younger
Golden Retrievers, chases squirrels, etc.  I've begun daily walks as part of his
recuperation - I've been keeping him still for the last 8 weeks to allow the
cruciate to heal.  BTW - $2000+ surgery was the immediate
recommendation from the vet upon examination.  I declined surgery because
I wasn't convinced he needed it, and did not want to put a 10 year old dog
through anesthesia, surgery and subsequent painful recovery.  Additionally,
he is on 2x daily thyroid medication.  My questions: does the glucosamine
and chondroitin really help a dog that may have limited sinovial joint fluid.  
Since it can't be replaced - what is the purpose of the supplement?   How
does it work in an older dog?  Also, any contraindications of any kind - for
age, for use with thyroid med, etc.  Thanks for any info you can provide.

Answer
Hi Lory,

Glucocorticoids, the group that Glucosamines and Chondroitin belong to, has been known to interfere some medications. You should talk to your veterinarian about using a these supplements while also receiving thyroid medication.

That said, owners of dogs who supplement with Glucosamine and Chondroitin seem to think it makes a significant difference in about half of the dogs that receive it. These treatments don't seem help all dogs, so it's really great that you're seeing such progress!

Joints, responsible for movement, are made up of a joint cavity filled with synovial fluid, a synovial membrane, and particular cartilage. The particular cartilage acts as a shock absorber and a smooth gliding surface for bones within the joint. The synovial fluid acts as both a lubricant and a source of nutrition for the cartilage. Cartilage is a matrix made up of collagen, hyaluronic acid (component of synovial fluid), and glycosaminoglycans. Because of the mechanical forces of movement and weight bearing, these matrix components are constantly being replenished in order to maintain strength and resilience. This rebuilding process creates a large demand for the building blocks utilized in this process. If these building blocks are not available in adequate levels, the process will breakdown, and eventually lead to degenerative joint disease.

Glucosamine is thought to be responsible for the synthesis of hyaluronic acid and glycosaminoglycans within the joint.
Chondroitin, while being one of the major gylcosaminoglycans, also acts to inhibit degenerative enzymes that promote the further breakdown of cartilage. This is why if the Glucosamine/Chondrotin is stopped, the degeneration will resume.

Chondroitin and Glucosamine are widely believed to stimulate the joint cells to produce better quality joint fluid (synovial fluid, which acts as a cushion), and to trigger the cartilage matrix to help prevent damage to the joints. These supplements can't cure an injury or degenerative joint disease, but in some dogs they can help, and your dog seems to be benefiting.

At the present time, studies seem to be saying that Chondroitin appears to be the more active of these two substances, so it would probably be best to use a medication containing both ingredients or to use Chondroitin if you choose between them because of the cost factor.

Chondroitin and Glucosamine do nothing to relieve pain. So in addition to these supplements, your dog might benefit from a pain medication, at least on a "as needed" basis. Get a recommendation from your vet, because Chondroitin and Glucosamine should not be used with certain pain killers.

Best of luck,

Patti