Picking a joint supplement for a dog with arthritis

How common is osteoarthritis in dogs?

Osteoarthritis affects a substantial share of the dog population. A 2024 cross-sectional radiographic study found OA prevalence of 38 to 40 percent in dogs older than 8 years, and a separate 2024 prospective study of 123 dogs aged 8 months to 4 years found radiographic signs of appendicular osteoarthritis in 39.8 percent of the group, published in Nature Scientific Reports. The condition can begin well before a dog is considered senior.

OA develops when cartilage, the smooth cushion between bones in a joint, breaks down. Without that buffer, bone grinds on bone, causing pain, stiffness and reduced mobility. The condition is progressive, and while research suggests certain supplements may help support joint comfort and function, the progression continues.

What does glucosamine do for dogs?

Glucosamine is an amino sugar and a building block of cartilage. The body produces it naturally, and supplemental forms are typically derived from shellfish shells or synthesized in a lab. Research suggests glucosamine may help support cartilage repair and reduce joint inflammation.

A 2007 randomized, double-blind, positive-controlled trial of 35 dogs with osteoarthritis, published in The Journal of Veterinary Pharmacology and Therapeutics, found that a glucosamine and chondroitin sulfate combination improved joint function scores over 70 days compared to baseline measures.

A more recent 2023 trial, published in Frontiers in Veterinary Science, enrolled 75 dogs with hip OA in a block-randomized, double-blinded, placebo-controlled design. One group received a combination of glucosamine hydrochloride, chondroitin sulfate and MSM. Over 120 days, the glucosamine group showed statistically significant improvement in lameness and mobility scores compared to placebo, and the improvement was comparable to dogs receiving carprofen, a nonsteroidal anti-inflammatory drug.

What is chondroitin sulfate?

Chondroitin sulfate is a major component of cartilage. It helps cartilage retain water and maintain elasticity. In supplement form, it is often paired with glucosamine.

The 2023 trial noted above used chondroitin sulfate alongside glucosamine and MSM, and the combination showed mobility benefits over the four-month study period. The study did not isolate chondroitin's effect, so we cannot say which ingredient drove the outcome, but the combined formula performed well.

What is MSM and does it help dogs?

MSM, or methylsulfonylmethane, is an organic sulfur compound found in plants, animals and humans. It is marketed as a joint supplement for both people and dogs, often combined with glucosamine and chondroitin.

The 2023 trial included MSM in the glucosamine-chondroitin formula, and that group showed improved mobility. However, the study did not test MSM alone, and no canine-specific randomized controlled trial isolating MSM was identified in the research reviewed. The evidence for MSM in dogs is weaker than for glucosamine and chondroitin.

Does CBD oil help dogs with joint pain?

Research suggests CBD may help support comfort in dogs with osteoarthritis, but the evidence base is still developing and study quality is a concern.

A 2018 randomized, placebo-controlled, double-blind crossover trial of 16 dogs with OA, conducted at Cornell University and published in Frontiers in Veterinary Science, found that CBD oil significantly decreased pain scores and increased activity levels over four weeks, as measured by veterinary assessments and owner questionnaires. No adverse effects were recorded in the trial.

A 2023 systematic review and meta-analysis pooled data from 5 studies covering 117 dogs, published in Frontiers in Veterinary Science. The review found that CBD showed a statistically significant reduction in pain scores compared to placebo, but all five studies were rated as high risk of bias, and the authors concluded that evidence quality remains weak.

CBD is not approved by the FDA for veterinary use. If you are considering CBD for your dog, check your state's laws and talk to your vet, especially if your dog is on other medications. The Cornell study used a hemp-derived CBD oil with less than 0.3 percent THC, the legal threshold in many jurisdictions.

Which breeds are at higher risk for joint disease?

Genetic predisposition plays a role. A 2010 study published in PLOS ONE analyzed 721 dogs across 8 pure breeds and identified genetic markers associated with hip dysplasia and osteoarthritis. The breeds studied were Labrador Retrievers, Golden Retrievers, German Shepherds, Rottweilers, Newfoundlands, Bernese Mountain Dogs, Greyhounds and Border Collies.

Large and giant breeds face higher risk due to rapid growth, body weight and joint stress. Hip dysplasia, a malformation of the hip joint, is a known precursor to OA in these breeds.

How much glucosamine should I give my dog?

The 2023 trial reported no adverse effects from the glucosamine-chondroitin-MSM combination over 120 days. However, optimal dosing may vary by product and individual dog. Some veterinary references suggest starting lower and adjusting based on response.

Do not dose based on a human supplement label. Use a product formulated for dogs, and talk to your vet before starting, especially if your dog has kidney disease, diabetes or is pregnant.

How much CBD oil should I give my dog?

The Cornell 2018 study dosed CBD oil and found it well tolerated.

CBD affects individual dogs differently, and product concentration varies widely. Start low, increase slowly, and monitor your dog's response. Talk to your vet before starting CBD, especially if your dog takes other medications, as CBD can interact with drugs metabolized by the liver.

Are there side effects?

Glucosamine and chondroitin are generally well tolerated. The 2023 trial of 75 dogs reported no adverse effects over 120 days. Some dogs may experience mild digestive upset when starting a new supplement.

The 2018 CBD trial recorded no adverse effects, but the 2023 systematic review noted that study designs were not robust enough to assess rare or long-term risks. Some dogs may experience sedation, dry mouth or changes in appetite on CBD.

If your dog shows vomiting, diarrhea, lethargy or other symptoms after starting a supplement, stop the product and call your vet.

When should I start giving my dog joint supplements?

Most veterinarians recommend waiting until skeletal maturity before starting joint supplements. Growth plates close between 12 and 24 months depending on breed, with large and giant breeds maturing later.

If your dog is predisposed to hip dysplasia or shows early signs of stiffness such as difficulty rising, reluctance to jump or a bunny-hop gait, talk to your vet about the right timing. Early intervention with weight management, controlled exercise and appropriate supplementation may help, but introducing supplements before skeletal maturity should be a veterinary decision.

What else helps dogs with osteoarthritis?

Weight management is critical. Excess body weight increases joint load and accelerates cartilage breakdown. A 2010 study found that maintaining lean body condition throughout life reduced the severity of hip OA in predisposed breeds.

Controlled, low-impact exercise such as swimming or short, frequent walks helps maintain muscle mass and joint mobility without overloading damaged cartilage. Physical therapy, including underwater treadmill work, is increasingly used in veterinary rehabilitation.

Prescription pain relievers, including nonsteroidal anti-inflammatory drugs such as carprofen, remain the standard of care for moderate to severe OA pain. Supplements may be used alongside medication, but any combination should be discussed with your vet.

Can I give my dog a joint supplement made for people?

Some active ingredients are the same, but human formulas may include fillers, sweeteners such as xylitol (which is toxic to dogs), or other compounds inappropriate for dogs. Dosing is also different.

Use a supplement formulated for dogs, and check the ingredient list for anything your dog should not have. Talk to your vet before starting any supplement, especially if your dog has kidney disease, liver disease, diabetes, or takes other medications.