Key takeaways
- Osteoarthritis is common in older dogs. Stiffness, slowing down and trouble with stairs are typical signs.
- Omega-3 fatty acids (from fish oil or omega-3-enriched diets) have the strongest evidence for easing arthritis pain in dogs.
- A large 2022 review found glucosamine and chondroitin did not relieve arthritis pain and should no longer be recommended for it.
- Keeping your dog lean is one of the most effective things you can do for its joints.
- Always check with your vet before starting a supplement, and never give dogs human products without asking.
Signs of joint problems in older dogs
Osteoarthritis (OA) develops gradually as the cartilage cushioning the joints wears down. Dogs are good at hiding pain, so early signs are easy to miss:
- Stiffness when getting up, especially after rest or in cold weather
- Hesitating at stairs, getting into the car or jumping onto furniture
- Walking more slowly or lagging behind on walks
- Limping, or shifting weight between legs
- Licking a particular joint
- Irritability when touched, or changes in mood
If you notice these signs, start with a vet visit. Your vet can confirm arthritis, rule out other problems and discuss pain relief. Supplements are add-ons, not a replacement for proper pain treatment.
What a major 2022 review found
In 2022, researchers at the University of Montreal published a systematic review and meta-analysis in the International Journal of Molecular Sciences. They analyzed 57 studies of therapeutic diets and nutraceuticals for osteoarthritis in dogs and cats. Most of the studies were in dogs.
| Supplement | Evidence in dogs | What the review found |
|---|---|---|
| Omega-3 fatty acids (fish oil, enriched diets) | Strong | Clear evidence of pain relief. The most consistent result in the review. |
| Green-lipped mussel | Moderate | Grouped with omega-3 products, since it's a source of omega-3s. Not analyzed on its own. |
| Cannabidiol (CBD) | Limited | Some effect, less than omega-3s. More research needed. |
| Collagen (undenatured type II) | Limited | Weak evidence, mostly from small, lower-quality studies. |
| Turmeric (curcumin) | Insufficient | Conflicting results. |
| Glucosamine and chondroitin | Insufficient | No pain relief found. The authors said they should no longer be recommended for OA pain. |
The authors also noted that many studies used subjective owner assessments rather than validated pain measures, which is a common weakness in this field.
Omega-3 fatty acids
The omega-3s EPA and DHA, found in fish oil, have anti-inflammatory effects. In dogs with arthritis, omega-3 supplements and prescription joint diets rich in fish oil have been shown to improve mobility and reduce pain in multiple studies.
What to know:
- Dosing is based on your dog's weight and on the combined amount of EPA and DHA, not the total fish oil. Ask your vet for the right dose.
- Possible side effects include diarrhea, a fishy smell and, at high doses, effects on blood clotting.
- Fish oil adds calories, which matters for overweight dogs.
- Prescription joint diets can be a simpler way to give omega-3s consistently.
Green-lipped mussel
Green-lipped mussel (Perna canaliculus) comes from New Zealand and contains omega-3s and other compounds. Several studies in dogs have reported improvements in arthritis signs. It's a reasonable option to discuss with your vet, especially if your dog won't eat fish oil. Avoid it if your dog has a shellfish allergy.
Glucosamine and chondroitin
These are the most widely sold joint supplements for dogs, and many owners report their dogs seem better on them. But controlled studies haven't shown a reliable effect on pain, and the 2022 review found essentially no benefit. They're generally safe, so if your vet is happy for your dog to continue, there's little harm. Just don't rely on them as your dog's main pain treatment.
Weight: the most important "supplement"
Extra weight puts more stress on painful joints. In a well-known lifetime study of Labrador Retrievers published in the Journal of the American Veterinary Medical Association in 2002, dogs kept lean through controlled feeding developed signs of osteoarthritis later and lived about two years longer, on average, than their littermates who ate more.
Ask your vet to assess your dog's body condition. For an overweight dog with arthritis, losing even a modest amount of weight can noticeably improve mobility.
Other things that help
- Regular, gentle exercise. Several short walks a day are better than one long one. Swimming is easy on joints.
- Non-slip floors. Rugs or runners on slippery floors help dogs move confidently.
- Ramps and steps for cars and furniture.
- A supportive, orthopedic bed away from drafts.
- Prescription pain relief. Your vet may prescribe anti-inflammatory medication or newer arthritis treatments. Never give your dog human painkillers such as ibuprofen, naproxen or acetaminophen. They can be toxic to dogs.
Choosing a joint supplement
- Choose products made for dogs, with the amount of each active ingredient clearly listed.
- For omega-3s, look for the EPA and DHA amounts per dose.
- Look for the National Animal Supplement Council (NASC) Quality Seal, which shows the company follows quality standards.
- Give a supplement 6 to 8 weeks before judging whether it's helping, and keep notes on your dog's mobility.
The bottom line
For older dogs with arthritis, the best-supported steps are keeping them lean, gentle regular exercise, vet-prescribed pain relief when needed and omega-3 fatty acids. Green-lipped mussel is a reasonable option. Glucosamine and chondroitin are safe but don't have good evidence for pain relief. Talk to your vet before starting any supplement so it fits safely with your dog's other treatments.