Osteoarthritis is by far the most common type of arthritis seen in small animal practice. It is properly known as degenerative joint disease (DJD), and involves a progressive deterioration of the articular cartilage in moveable joints. It is mainly a problem affecting older animals. Osteoarthritis is a disease which results in changes in the joints leading to pain, stiffness and a reduction in joint flexibility. The cartilage of movable joints changes and deteriorates especially as the animal ages and there are areas of erosion of cartilage together with areas of abnormal deposition of bone.
Osteoarthritis may be primary (idiopathic) or secondary in nature. Primary osteoarthritis is rare and is due to some inherited predisposition towards the problem. Certain breeds of cat have a tendency to develop arthritis because of some inherited anatomical problem. For example some breed lines of the Burmese cat are prone to hip dysplasia with the subsequent development of osteoarthritis. If you are purchasing a new pedigree cat it would be worth asking the breeder if they have any problems with osteoarthritis in their breed line. Non-pedigree animals do not tend to suffer from primary osteoarthritis so frequently.
Secondary osteoarthritis is very common and tends to occur following a preceding problem or injury to the joint such as an infection, a fracture, trauma or abnormal stress during movement of the joint.
Osteoarthritis is often noticed when the cat becomes lame. This is much easier to spot when only one joint is affected because the gait will become noticeably abnormal with the "favoring" of a limb, expressed as a dropping of a hip or the nodding of the head when walking. If more than one joint is affected the cat may just walk more carefully and slowly or may just become less active altogether; in this case the problem is considerably more difficult to spot. One of the most classic signs of osteoarthritic conditions is that the animal will be very stiff and find movement difficult following rest or sleep but will improve once they start to move around. Sometimes the problem comes to light when a cat is less able to jump onto fences or other high surfaces, even their favorite chair may become a struggle to reach. Cats do not often cry out in pain when affected with arthritis but they may become irritable, nervous and less active generally because they are in chronic pain. If your cat shows any of these signs or just seems to be slowing down and getting old arthritis is a likely cause.
Vets will examine your pet for signs of arthritis if it is suspected and can often diagnose it without x-rays or further tests. We manipulate the joints gently to check for swellings, heat, evidence of pain, range of movement and crepitus (a grating feeling when the joint is manipulated). Sometimes it is necessary to take an x-ray to find out what is going on in the joints, although often the extent of damage seen on an x-ray does not correlate with the signs of pain expressed by the animal! Occasionally it is necessary to take a sample of the fluid within the joint to check for infection.
If your cat has osteoarthritis it is important that it does not become plump, since fat cats have much more stress on their joints due to this extra weight. Also the cat should have a moderate amount of exercise. These two things are extremely helpful but initially may be difficult for the owner to encourage. A cat in pain with arthritis probably wants to rest much of the time and will probably be carrying too much weight as a result of its inactive lifestyle. Cut back on food first to promote weight loss and then as movement naturally becomes easier encourage exercise.
Osteoarthritis may be treated with medication. This will only control the signs of the condition, it cannot be cured.
Most of the drugs used in osteoarthritis are analgesics (pain killers), which help the animal to function more normally but do not change the underlying pathology of the joint. Various pain control regimes can be tried and the drug most effective for your pet can be found.
Therapy for osteoarthritis often involves the use of NSAIDS or non-steroidal anti-inflammatory drugs. Very few of these drugs are licensed for use in the cat and long term use may cause problems such as gastrointestinal upsets. They are usually given long term by mouth and should be given with food. Injections can be given but this is only really practical for short term use. Care should be taken with these drugs and the risk versus benefits carefully weighed up. If your cat has kidney, liver or heart problems, a blood clotting disorder or a gastric ulcer these drugs may need to be avoided. NSAIDS should not be given with steroids.
Steroids are sometimes used to alleviate inflammatory erosive osteoarthritis. They help by suppressing the inflammatory changes on the cartilage of the joint. Long term use of corticosteroids should be avoided if possible. Again the benefits of the drugs should be weighed against the risks and an assessment made for each individual animal.
Polysulphated glycosaminoglycans (PSGAGs) and hyaluronic acid derivatives may also be used in osteoarthritic conditions.
Sometimes surgical treatment is possible but this only applies to specific conditions and where the arthritis is limited to a particular joint. Surgery can be particularly successful in the treatment of severe arthritic conditions of the hip joint in cats. Surgery would be an unlikely first line of treatment because surgery involving the joints may in itself predispose the joint to develop osteoarthritis.
There are alternative complementary therapies available for osteoarthritis. Nutraceuticals are very often used in this condition. These will be covered in the alternative medicine section of the web site.