Glossary

Osteoarthritis

Wear and inflammation of the joints that is very common in older cats and often shows up as subtle changes in behavior.

Also called: arthritis, degenerative joint disease, DJD, cat arthritis

Osteoarthritis is a condition in which the cartilage that cushions a joint wears down, the bone underneath changes, and the joint becomes inflamed and painful. X-ray studies of older cats find it in a large majority, and it can also follow injuries, or occur in young cats with joint malformations. Excess weight puts more stress on the joints, so obesity makes it worse.

Cats rarely limp. Owners instead notice subtle changes: jumping less or choosing lower perches, stiffness after rest, trouble with stairs, missing the litter box or struggling with a high-sided one, less grooming with a matted or greasy back, sleeping more, irritability or hiding. These are often put down to old age, but they can mean pain that is treatable.

A vet makes the diagnosis from the history, an orthopedic exam and sometimes X-rays. Care combines pain relief prescribed by the vet, weight control, a comfortable home and sometimes physical therapy or injections. Never give a cat human painkillers such as acetaminophen or ibuprofen, since they can be fatal. Easy changes at home include a low-sided litter box, steps up to favorite spots, and soft, warm bedding. Ask your vet about a pain plan and about using a quality of life check to see if it is working.

Last reviewed November 7, 2026

In the index now

Related terms

Obesity Excess body fat that harms a cat's health, raising the risk of diabetes, arthritis and urinary disease. Body condition score A hands-on rating of how lean or fat a cat is, on a scale such as 1 to 9, used by vets because weight alone can mislead. Quality of life A way of judging whether a sick or elderly cat is still comfortable and enjoying life, used to guide end-of-life decisions. Wellness exam A routine vet visit for a healthy-looking cat to check its body, update vaccines and parasite control, and catch problems early. Hospice care Care for a cat with an incurable illness that focuses on comfort, pain relief and quality of life rather than cure.

Related guides

Caring for a senior cat How to adjust food, vet visits, litter boxes and daily life as your cat ages, and which changes mean a call to the vet. Keeping a cat warm in cold weather How to keep indoor and outdoor cats warm in winter, the winter hazards to watch for, and the signs of cold stress that need a vet. When a cat pees outside the litter box Why a cat urinates outside the litter box, why a vet check comes first, how to tell it from spraying, and the steps that fix box problems in the home.