Arthritis in cats: the pain almost nobody sees
For years, arthritis was thought to be a dog thing. Today we know it affects the vast majority of elderly cats, but they hide it so well that it is hardly ever diagnosed. If your cat no longer jumps the way they used to, it may not be age: it may be pain.
Far more common than people think
Osteoarthritis, or degenerative joint disease, is the progressive wearing away of the cartilage in the joints, with inflammation and pain. In X-ray studies, the great majority of cats over twelve show signs of arthritis, as do a significant proportion of middle-aged cats. The joints most affected are the elbows, hips, knees, hocks and spine. Age, obesity, old injuries such as fractures or falls, and some breeds all play a part: Scottish Folds suffer a cartilage disease linked to the mutation that folds their ears, which causes severe arthritis from a young age, and the Maine Coon and Persian have more hip dysplasia.
Why they almost never limp
A cat spreads its weight over four legs, is light and very good at adapting, so instead of limping they change how they move and their routine. On top of that, as a hunter that is also prey, hiding pain is in their nature. At the clinic, stressed, the cat stays still on the table and it is very hard to see anything. That is why diagnosing feline arthritis depends much more on what you notice at home than on what the vet sees in a ten-minute appointment. What you tell them is the most important part.
The signs at home
Jumping less or no longer jumping onto high places; going up in two stages, onto a chair first; getting down carefully or sideways; hesitating before jumping. Going up and down stairs more slowly. Sleeping more and playing less. Grooming less, especially the back and hindquarters, or licking a lot over one joint. Toileting outside the litter tray because getting in or crouching is hard. Using the scratching post less and having long claws. Being more irritable when touched or picked up, or keeping away from other cats. There are validated questionnaires for owners, such as the Feline Musculoskeletal Pain Index (FMPI), that help put it into numbers. If you recognise several of these signs, mention them to your vet and, if you can, film the cat going up and down at home.
How it is diagnosed
With the history of what you see at home, an orthopaedic examination in which the vet feels and moves each joint looking for pain, thickening or reduced movement, and sometimes X-rays. X-rays do not always match the pain: some cats have striking X-rays and little pain, and vice versa. That is why the most useful test is often a treatment trial: treating the pain for a few weeks and seeing whether the cat changes. If they start jumping, playing or grooming again, the diagnosis is clear. Before starting treatment, older cats usually have blood tests to check how their kidneys are doing.
Current treatments
There are two main veterinary options, and choosing between them is for the vet to decide based on the cat's health. Non-steroidal anti-inflammatories licensed for cats are effective, although in cats with kidney disease they must be used with caution and monitoring. Since 2021, a monoclonal antibody against nerve growth factor (NGF) has been available in Europe, licensed for arthritis pain in cats; it is given as a monthly injection at the clinic and in studies it improves mobility and activity in many cats, and is well tolerated. These can be combined with other measures and, in complex cases, with other painkillers. In some cats the change is spectacular: they start behaving as they did years ago.
Never human painkillers
This is the most important warning in this article. Paracetamol is deadly to cats even in tiny doses: their liver cannot break it down and it destroys red blood cells and the liver itself within hours. Ibuprofen, naproxen, diclofenac, aspirin and other human anti-inflammatories cause stomach ulcers and kidney failure in cats. Do not give your dog's anti-inflammatories either: although some active ingredients are used in both species, the formulation and the way they are used are different. Any pain medicine for a cat must be prescribed by a vet for that particular cat.
Weight: the cheapest treatment
Every extra kilo (about 2 lb) is added load on joints that are already damaged, and fat also produces inflammatory substances. In an obese cat with arthritis, losing weight improves pain and mobility noticeably. It must be done gradually, with the diet and pace set by the vet, because in cats losing weight too fast can trigger hepatic lipidosis. Marine omega-3 fatty acids, in veterinary joint diets or as a supplement, have some evidence of helping. Other supplements, such as glucosamine or chondroitin, have weaker evidence in cats.
Adapting the home
Ramps, steps or intermediate furniture so they can reach their favourite high spots without jumping. Large litter trays with a low side or a cut-out entrance, on every floor of the home. Food and water bowls at a comfortable height, without having to climb onto the worktop. Soft, warm beds in draught-free places, and pet heat pads in winter. Rugs on slippery floors. Horizontal or sloping scratchers as well as vertical ones. Help with brushing the areas they cannot reach and trim their claws often. And gentle play at ground level so they keep their muscle without overdoing it.
What it costs
As a guide in Spain in 2026: consultation with an orthopaedic examination, 40 to 70 €; X-rays, 60 to 150 €; pre-treatment blood tests, 80 to 160 €. The monthly monoclonal antibody usually costs between 50 and 100 € per injection depending on weight and clinic. Veterinary anti-inflammatories for cats, 15 to 40 € a month, plus monitoring blood tests. Home adaptations can be done for very little money: a low storage box as a litter tray or a stool as a step works just as well as more expensive products. The aim is not just for them to live longer, but to live without pain.
Most older cats have arthritis and hardly any of them limp: what you see is jumping less, grooming less or toileting outside the tray. Today there are effective, safe treatments for cats, including a monthly injection. A healthy weight, an adapted home and never human painkillers.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.