Degenerative Joint Disease in Cats

The main function of joints is to allow flexibility and motion to the skeleton or to allow growth.  Some joints do not move, such as the fixed joints of the plates of bone that make up the skull.  Others have somewhat restricted movement like those between the vertebrae.  Most joints allow a much greater range of motion like hips, knees, elbows, and shoulders.

Many joints have complex components to their structure more than just the ends of the bones connected by a joint.  Joints are held together by tough fibrous ligaments that make the structural connection between the bones.  The ends of the bones are covered with cartilage which provides a covering and cushioning for them.  Joints are surrounded by a fibrous capsule which is lined with a synovial membrane that secretes a lubricating fluid to allow smooth movement of the joint.

Degenerative joint disease (DJD) is also known as osteoarthritis. It usually involves a deterioration of the quality of the lubricant synovial fluid, a resultant thinning and break-down of the cartilage cushion that protects the ends of the bones and inflammation of the joint.  It can be brought on as a result of being overweight, normal aging, or there may be a genetic component in certain individuals.  90% of cats have some degree of DJD by the time they reach the age of ten.  Just as in humans, it is a painful condition and pain can have a serious effect on mood, behavior, and mobility.

Most cases of DJD can be alleviated to some extent with medications.  Cartrophen is an injectable medication that stimulates production of cartilage, improves the quality of synovial fluid, inhibits enzymes involved in the degradation of cartilage, reduces inflammation, and improves circulation of blood to the bones of the joint.  Injections are given once weekly for four weeks and then once monthly thereafter.  The amounts injected are tiny and can easily be done at home once the cat’s care giver has been shown how to do it.  It is a relatively safe medication with few side effects and the fact that it can be administered once monthly instead of daily makes treatment easy and convenient.

While cartrophen works to replace the fluid-filled joint cushion, we also recommend analgesic (pain) medication.   Metacam is an NSAID (Non-Steroidal Anti Inflammatory Drug) available for cats.  Metacam (Meloxicam) is easily administered orally in liquid form once daily.  It is tasteless and can be given with food.  NSAIDs have the potential of causing intestinal upsets and kidney damage but these are rare if the proper dosage is administered.  Before starting treatment with meloxicam it is prudent to do an analysis of Blood Chemistry, Complete Blood Count and Urine Analysis to be sure that it is safe to administer the medication.  Likewise, these tests should be done at least once annually to ensure that it is safe to continue treatment.  If lab tests reveal that Metacam is not the best choice for pain relief, we offer a number of other options.  Most notably, we may suggest the centrally-acting medication gabapentin for pain control.

As in humans, for arthritis of the hip joint (DJD) in certain patients, it is possible to perform a total hip replacement.  Calgary has specialist surgeons who perform this operation.