Osteoarthritis is a joint disease in which the cartilages (fibrous caps) covering the articular surfaces of the bones degenerate and bony proliferation (excess bone growth) occurs. This condition usually results in pain and lameness of the joints involved. It may occur in single joints of young animals with congenital joint defects or following any kind of joint trauma. When it occurs as an aging change it usually affects several joints, although lameness may not be apparent in all of them.
The lameness present with arthritis is often most severe on arising and improves with exercise. Sometimes all you will notice in your cat is a generally decreased ability to move freely or jump effectively. If you gently move the affected joints you may hear or feel crepitus (cartilage or bone grating against cartilage and/or bone). X-ray pictures will show the affected joints and the severity of bone changes. Although you may not become aware of the disease until signs occur, the changes characteristic of arthritis have usually been occurring over a long prior period.
There is no effective means of arresting the progression of osteoarthritis in older cats, so treatment is usually symptomatic, directed at relieving any significant pain and assisting the cat in getting to his or her favorite resting spot. Unfortunately most drugs useful for the symptomatic relief of arthritis in people, dogs, and other animals are toxic to cats. One of the safest drugs for people or dogs, aspirin, can cause severe signs of illness in cats and should only be used with care under the direction of a veterinarian.
Fortunately, few cats with osteoarthritis show discomfort and intermittent lameness or lameness that is only present on arising usually needs no treatment. Weight reduction often significantly improves lameness in obese cats with arthritis. Soft bedding, warm, dry quarters, and access to a towel-covered heating pad set at a safe, low temperature also help relieve discomfort. Acupuncture may help cats who don’t respond to more conventional treatments, as do some nutritional supplements with antiinflammatory effects. Ask your veterinarian what is appropriate for your cat.