Arthritis in cats is overwhelmingly common and driven by a combination of age-related wear, genetics, body weight, injury, and occasionally infection. Research from NC State University found that 90% of cats over 12 years old show evidence of arthritis on X-rays, and a follow-up study found that just over 90% of all cats have radiographic signs of degenerative joint disease somewhere in the body. Most cat owners never realize it, because cats are exceptionally good at hiding pain.
How Joint Breakdown Works in Cats
The most common form of arthritis in cats is osteoarthritis, also called degenerative joint disease. Healthy joints have a layer of smooth cartilage covering the ends of bones, allowing them to glide against each other with minimal friction. Over time, that cartilage wears down, thins, and develops small cracks. Without that cushion, bone grinds on bone, triggering inflammation, pain, and the formation of bony spurs around the joint.
This process feeds on itself. Inflammation in the joint releases chemical signals that break down cartilage even faster, while the body’s attempt to stabilize the joint by growing extra bone only makes it stiffer and more painful. The hips, elbows, knees, and spine are the most frequently affected areas. Unlike dogs, who tend to limp obviously, cats typically just become less active, making the problem easy to miss for years.
Age Is the Biggest Factor
Joint cartilage naturally deteriorates with time. Cats as young as six can show early signs on X-rays, but the condition becomes nearly universal in senior cats. By the time a cat reaches 12, the odds of having some degree of arthritis are around 90%. This doesn’t mean every older cat is in severe pain, but it does mean the joints are changing. The rate at which those changes become painful varies by cat and depends heavily on other risk factors stacking up alongside age.
Obesity and Chronic Inflammation
Excess weight damages joints in two ways. The obvious one is mechanical: heavier cats put more force through their joints with every step and every jump, accelerating cartilage breakdown. The less obvious one is chemical. Fat tissue isn’t just stored energy. It actively produces inflammatory molecules, including compounds like TNF-alpha and several interleukins, that circulate through the body and attack joint tissue from the inside.
In overweight cats, enlarged fat cells trigger a cascade of immune responses. Immune cells infiltrate the fat tissue in greater numbers than they would in lean cats, ramping up the production of these inflammatory signals. The result is a state of chronic, low-grade inflammation throughout the body. This systemic inflammation doesn’t just contribute to arthritis. It also raises the risk of diabetes and heart disease. But for the joints specifically, it means cartilage is being degraded both by physical stress from above and by inflammatory chemicals from within, a combination that speeds up the disease considerably.
Genetics and Breed Risks
Genetics, breed, and even sex play a role in which cats develop arthritis and how quickly it progresses. The clearest example is Scottish Folds. The gene responsible for their distinctive folded ears also causes a cartilage defect throughout the body, leading to a condition called osteodystrophy. This can produce severe, painful joint disease even in young cats, sometimes requiring surgical intervention.
Other breeds with known skeletal vulnerabilities, such as Maine Coons (who are prone to hip dysplasia) and certain purebreds with compact or extreme body proportions, also face elevated risk. That said, the research on breed-specific arthritis risk in cats is less developed than in dogs. Diet, environment, and whether a cat has been spayed or neutered are all considered contributing factors, though their individual impact hasn’t been as clearly measured in cats as in other species.
Hip Dysplasia and Structural Problems
Hip dysplasia is recognized as an inherited condition in cats, though it often goes undiagnosed because cats compensate so well for pelvic limb pain. In a dysplastic hip, the ball and socket don’t fit together properly, creating abnormal movement and uneven stress on the cartilage. Over time, this mismatch leads to osteoarthritis in the hip joint.
Patellar luxation, where the kneecap slides out of its normal groove, is another structural issue linked to arthritis. Research shows that cats are three times more likely to have both hip dysplasia and patellar luxation together than either condition alone. A displaced kneecap can alter the forces traveling up the leg, potentially contributing to hip problems as well. Both conditions are polygenic, meaning they’re influenced by multiple genes, and environmental factors can worsen the physical expression of the disease even if they don’t cause it directly.
Injuries and Trauma
Any joint injury can set the stage for arthritis later. Cruciate ligament ruptures in cats most often result from falls, particularly in cats who fall from significant heights (sometimes called “high-rise syndrome”). These injuries rarely happen in isolation. When a cat ruptures a cruciate ligament, the damage typically includes tears to other ligaments and the meniscus, with meniscal injuries occurring in at least 50% of cases.
Even after the initial injury heals, the joint is never quite the same. The altered mechanics, scar tissue, and residual instability cause the cartilage to wear unevenly, and degenerative joint disease develops in the months or years that follow. Fractures that extend into a joint surface, dislocations, and even repeated minor sprains can all produce the same long-term outcome.
Viral Infections and Immune-Related Arthritis
Not all feline arthritis is degenerative. Feline calicivirus, a common respiratory pathogen, can cause a condition known as “limping syndrome,” where the virus infects the joint lining and triggers painful inflammation in multiple joints at once. This can happen during a natural infection or, less commonly, after vaccination.
In most cases, the limping resolves within days to weeks. But research has documented cases where calicivirus persisted in the joint tissue for months, with the virus found inside cells of the synovial membrane (the tissue lining the joint). One documented case showed ongoing inflammation and osteoarthritis eight months after the initial infection, suggesting that in rare instances, a viral joint infection can become chronic and cause lasting structural damage. The virus doesn’t appear to need to belong to any particular genetic subgroup to trigger joint problems.
Hormonal and Metabolic Causes
Acromegaly, a condition caused by excess growth hormone, is an uncommon but recognized cause of joint disease in cats. The excess growth hormone drives continuous growth and widening of the extremities, thickening joint cartilage abnormally and eventually causing arthritis and spinal changes known as spondylosis deformans. Acromegaly in cats is most often linked to a pituitary tumor and frequently shows up alongside difficult-to-control diabetes. The joint problems in these cases are secondary to the hormonal disorder and tend to improve when the underlying condition is managed.
Signs That Point to Joint Pain
Cats rarely limp the way dogs do. Instead, arthritis shows up as behavioral changes that are easy to dismiss as “just getting older.” Reduced grooming is one of the most reliable indicators, especially matting along the back or hind legs where a stiff cat can’t reach. Difficulty jumping, or jumping to lower surfaces than before, is another strong signal. A cat that once leaped onto the counter but now only makes it to the couch is likely dealing with joint pain.
Litter box avoidance is a subtler sign. Cats with painful hips or knees may struggle to step over the sides of a standard litter box, or the posture required to use one may be uncomfortable enough that they start going elsewhere. Changes in sleep patterns, irritability when touched in certain areas, and a general withdrawal from activity round out the picture. Because these signs develop gradually, many owners attribute them to aging rather than a treatable condition.