Arthritis – especially the degenerative form of this inflammatory joint disease – is fairly common in domestic cats. Fortunately, arthritis is not particularly difficult to diagnose. In most cases, owners bring their aging cats to a veterinarian because they have noticed that they are stiff, reluctant to rise and are just generally starting to slow down. They may have problems jumping up onto furniture, grooming themselves or getting into and out of the litter box. The doctor will ask the owner about the cat’s general health, when its current symptoms started and whether they have waxed and waned, stayed about the same or steadily gotten worse. After taking a thorough history, the veterinarian will carefully examine the cat, paying particular attention to its limbs, back and joints. She will be looking for swelling, heat and signs of discomfort. A complete physical examination will help to localize the site of the joint inflammation. Usually, the cat’s history, presenting symptoms and physical examination results will point to a tentative diagnosis of arthritis.
After the history and physical examination are completed, the typical initial data base for aging feline patients includes taking blood and urine samples and submitting them to a laboratory for blood work and a urinalysis. These routine tests usually don’t provide much diagnostic information about the overall condition of cats with arthritis or the causes of their discomfort, although they can help rule out other possible causes, such as joint infections, and may provide valuable information about the cat’s geriatric baseline health. Radiographs, commonly called X-rays, are a very effective tool for identifying and assessing the degree of arthritis; they can show changes in the joint capsules, soft tissue thickening and mineralization, narrowing of joint spaces, joint effusion (fluid build-up), changes in the cartilage that connects bones in joints, other bony changes, intra-articular calcified bodies (osteophytes) and other physical changes that are known to be associated with this disease. Unfortunately, the degree of abnormalities that can be seen on radiographs does not necessarily correlate to the severity of the cat’s clinical disease or to how poorly it feels. Another procedure, called bone nuclear scintigraphy, can help the veterinarian localize arthritic sites. Sampling and analysis of synovial fluid, which is the fluid lining and lubricating the inside of the joint capsule, can help determine the degree of inflammation and whether the joints are infected. Magnetic resonance imaging (MRI) and computed tomography (CT) are also available in specialized referral clinics and veterinary teaching hospitals to visualize joint incongruity, physical cartilage changes and the overall extent of the cat’s arthritis.
Arthritis in cats is almost always progressive and irreversible. Fortunately, there are a number of ways to manage this condition and help most affected animals maintain a good and relatively pain-free quality of life.