Cat osteoarthritis: what natural options help? Evidence review
Cat osteoarthritis: evidence on natural options like fish oil, green-lipped mussel and CBD. Honest, evidence-based guidance for owners.
Short & honest
Over 90% of older cats have joint wear, but pain is rarely recognised. Evidence for natural options is weak (grade C): fish oil and a GLM supplement showed positive effects in small studies; CBD is promising but too early for routine use.
Veterinary review not yet completed
This page is awaiting review by a registered veterinary surgeon. Until then, treat the text as education based on the sources listed — not as a verified veterinary judgement.
What is osteoarthritis in cats?
Osteoarthritis is wear of the cartilage in joints, causing bones to experience friction and chronic pain to develop. Radiologically, the condition is extremely widespread: more than 90% of cats older than 12 years show joint abnormalities on X-rays. Nevertheless, osteoarthritis in cats is missed far more often than in dogs, because cats naturally hide pain.
Recognising early signs
Cats do not complain. Subtle behavioural changes are often the first sign:
- Jumping less high or less frequently
- Reduced self-grooming of the back and tail (less reachable)
- Resting more often in a different, lower place
- Withdrawn behaviour or reacting irritably to touch instead
What does the evidence say?
Omega-3 fatty acids (EPA/DHA) from fish oil — limited positive evidence
In a randomised double-blind crossover study in 16 cats with osteoarthritis, activity, the ability to jump and stair use improved significantly after fish oil supplementation [1]. The study is small, but the design is methodologically sound. Fish oil is relatively safe for cats; consult the veterinary surgeon about dosage.
Green-lipped mussel, curcumin and blackcurrant leaf — limited positive evidence
A supplement with these three ingredients improved mobility, self-grooming and playfulness in a double-blind crossover study in 16 cats [2]. The effect was partial: not all cats responded. The same caveat as for fish oil: small, crossover, no long-term data.
CBD/CBDA (cannabidiol) — promising, insufficient for routine use
A placebo-controlled crossover study showed a significant reduction in pain scores after CBD/CBDA paste [3]. At the same time, 46% of cats dropped out due to gastrointestinal complaints or taste problems. CBD in cats is not yet sufficiently studied for routine application; use only under supervision of a veterinary surgeon.
Weight management — essential, no study needed
Every extra kilogram substantially increases joint loading in the relatively small build of cats. Weight reduction in cases of overweight is one of the few interventions that is broadly supported as part of every treatment plan.
What does not work or has not been investigated?
There is no good evidence for homeopathy, arnica, or arbitrary 'joint supplements' without demonstrated active ingredients in cats. Glucosamine and chondroitin are popular but lack robust clinical data specifically for cats.
Painkillers and safety
NSAIDs (such as meloxicam) are not routinely safe in cats with long-term use; regular kidney function monitoring by a veterinary surgeon is mandatory. Never give human NSAIDs (ibuprofen, naproxen, diclofenac) to cats — this can be fatal.
Adjunctive, not replacement
Natural options can form part of a broader approach, but do not replace veterinary diagnosis and supervision. Osteoarthritis is a progressive condition; without proper pain management, the cat suffers silently.
Sources: [1] Corbee et al. 2013, J Anim Physiol Anim Nutr · [2] Corbee et al. 2022, Vet Med Sci · [3] Mulder et al. 2025, J Feline Med Surg
Why this verdict?
The available evidence consists of small randomised double-blind crossover studies (n=16) for fish oil [1] and the GLM/curcumin supplement [2], and one placebo-controlled study for CBD in cats [3]. Crossover designs with such small groups provide indications but not robust evidence; a 46% dropout rate in the CBD study further limits utility. Consequently, the overall grade is C: weak but not negligible evidence.
Interactions with medication
- High-dose fish oil may affect blood clotting; use with caution alongside anticoagulants or before surgery
- CBD may affect liver-metabolising enzymes (CYP450), thereby altering concentrations of other medications; consult a veterinary surgeon when used concurrently with other agents
Legal status (Netherlands)
In the Netherlands, CBD products for animals fall under varying regulations; check whether the product is authorised as a feed supplement. Green-lipped mussel and fish oil are freely available as supplements.
Sources
- [1] The effect of dietary long-chain omega-3 fatty acid supplementation on owner's perception of behaviour and locomotion in cats with naturally occurring osteoarthritis. Journal of Animal Physiology and Animal Nutrition (Wiley), 2013. RCT source ↗
- [2] The efficacy of a nutritional supplement containing green-lipped mussel, curcumin and blackcurrant leaf extract in dogs and cats with osteoarthritis. Veterinary Medicine and Science (Wiley / PMC), 2022. RCT doi:10.1002/vms3.779
- [3] Field safety and efficacy study with a cannabidiol/cannabidiol acid-rich hemp paste in cats with osteoarthritic pain. Journal of Feline Medicine and Surgery (JFMS / PMC), 2025. RCT doi:10.1177/1098612X251367629