Why do some dog owners give their dogs joint supplements?

If a canine has arthritis or another form of joint pain, he'll probably have trouble moving around. Joint supplements can help a dog with this problem move more easily and reduce the amount of pain he feels when he does so.

What is in these supplements?

Joint supplements for dogs contain glucosamine or chondroitin sulfate, MSM (methylsulfonylmethane), manganese ascorbate, avocado/soybean unsaponifiables (ASUs), green lipped mussel extract, omega-3 fatty acids, decaffeinated tea extracts (polyphenols) including EGCG (epigallocatechin gallate). Some also contain vitamin C, Boswellia serrata (Indian frankincense), curcumin, yucca schidigera extract, proteolytic enzymes including trypsin and chymotrypsin.

What are the benefits?

Researchers have conducted several studies on dogs with osteoarthritis to determine if supplementing their diet with glucosamine or chondroitin sulfate improves any of these factors:

  • Physical examination findings, such as lameness
  • Radiographs (x-rays) showing signs of arthritis
  • Range of motion in the limbs
  • Pain, based on subjective owner assessments and/or objective measurements of pain during movement (based on force plate analysis)
  • Blood and urine markers of cartilage degradation


Based on this research, veterinarians have concluded that:

  • Dogs supplementing with glucosamine or chondroitin sulfate show improvement in gait score (how a dog moves) as well as reductions in lameness and pain post-exercise.
  • Adding omega 3 fatty acids for dogs to the diet leads to increased range of motion and improved grip strength.
  • Supplementing with ASUs significantly decreases lameness scores, increases activity levels, and improves weight bearing ability. However, these effects may not be due to a direct effect on arthritis itself but may instead be secondary benefits from lessening muscle atrophy that can accompany long periods of immobility.
  • Adding green lipped mussel extract to the diet can reduce pain and increase grip strength.
  • Adding avocado/soybean unsaponifiables (ASUs) to the diet reduces pain, improves range of motion, and increases short-term activity levels.
  • Glucosamine/chondroitin sulfate supplements are safe for dogs with healthy kidneys but should not be used if a dog has renal disease. Consult your veterinarian before giving your pet any type of supplement.

What about homemade supplements?

Many dog owners make their own supplements by grinding up whole chondroitin sulfate pills in a coffee grinder and mixing this in with their dog's food. This can be effective but is also very expensive, since you'll need to give much higher amounts of whole chondroitin sulfate to get the same effect as you'd get from a commercial supplement that only contains 10 percent actual chondroitin sulfate. Also, whole chondroitin sulfate is not water-soluble so may not be absorbed well by your pet's body.

A better alternative is to use a commercial supplement designed for dogs that contains both glucosamine and chondin sulfate in a low enough amount to be effective but not so high that you'd need to feed a whole lot of pills. For example, we can recommend hip and joint chews for dogs by KinpurPetCare. They contain all the natural substances you need to support your dog's joint health and can be easily fed to your dog as they taste and smell delicious to your pet.

What about human supplements?

Some people give their dogs glucosamine and chondroitin sulfate that they buy at the drugstore or health food store, since this type of supplement is safe and inexpensive. However, these products are formulated for humans and there's evidence that we metabolize them differently than dogs do. Glucosamine/chondroitin sulfate supplements designed for humans may also contain other compounds such as methylsulfonylmethane (MSM) which can cause stomach upset in pets if given in large enough doses. Administering high-dose aspirin therapy to dogs with arthritis may lead to gastrointestinal ulceration, so do not give your dog aspirin or products containing aspirin without veterinary guidance.

If you choose to try a human glucosamine/chondroitin sulfate supplement, use only the lowest dose formulated for humans and watch your dog carefully for signs of stomach upset. If giving these supplements, buy them in pill form rather than powder or granules that can be accidentally inhaled or ingested by accident when they are left within your pet's reach.

What about chondroprotectives?

Chondroprotectives are natural extracts derived from vegetables such as avocado and soybeans that have been shown to block enzymes linked to cartilage destruction in laboratory research studies. Avocado/soybean unsaponifiables (ASUs) are one type of chondroprotectives, but they are expensive and not very stable.

Another type of chondroprotecor is a compound called N-acetylglucosamine (NAG), which veterinary researchers believe might have the ability to block cartilage breakdown in dogs with osteoarthritis. However, as of this writing there is no research confirming the safety or efficacy of using NAG supplements for dogs. Speak to your veterinarian before giving your pet any type of supplement containing NAG.

In summary

The information reviewed by veterinarians shows that glucosamine and chondroitin sulfate can improve gait score as well as reduce pain and lameness associated with degenerative joint disease in dogs. However, the evidence is not entirely consistent and studies have had mixed results when they were done by different research teams.

The evidence that adding avocado/soybean unsaponifiables (ASUs) to your dog's diet can improve cartilage health or reduce arthritis pain has only come from one study so far. The evidence for NAG supplements consisting of chondroprotectives is even weaker than that for ASUs. However, this class of supplement shows interesting promise based on laboratory research data and it deserves further study to see if it can safely help delay or prevent osteoarthritis in dogs.

Finally, glucosamine/chondroitin sulfate supplements designed for pets are safe and extremely well-tolerated by most dogs who take them, so they are the supplements of choice if you're interested in giving your dog something to manage osteoarthritis pain.