What is it?
•Osteoarthritis is also known as degenerative joint disease (DJD)
•Osteoarthritis (OA) causes instability or pain in joints as a result of the degeneration of the cartilage within a joint
•Primary OA is not common in dogs or cats, but occurs with old age as a result of wear and tear in an otherwise normal joint
•Secondary OA is very common in both dogs and cats, and results from abnormalities or congenital defect in the joint such as hip or elbow dysplasia •OA can affect any joint, although most common are hips, knees, elbows, and shoulders 

What causes it?
•Osteoarthritis develops and worsens over months or sometimes years
•Any injury that leads to damage of the joint and surrounding structures may eventually lead to OA
•Some common conditions that can lead to OA are hip dysplasia, cranial cruciate ligament disease, osteochondritis dissecans, direct trauma or dislocation, or certain metabolic bone diseases
•Symptoms include lameness, muscle atrophy, difficulty getting up or lying down, loss of appetite, stiffness, pain, and cracking or popping of the affected joint 

What tests are needed?
•Based on history and clinical signs, a veterinarian can typically identify the disorder
•X-rays may be necessary to confirm diagnosis
•In some cases, fluid can be retrieved to confirm diagnosis by analysis, although with OA joint fluid is not actively inflamed 

How is it treated?
•OA can be treated medically or surgically, such as hip replacement in a dog
•Physical therapy, which can decrease stress on the joint, improves range of motion, and decreases pain
•Low-impact exercise can help the animal lose weight and reduce stress on the joint
•Supplements are available to decrease chronic degenerative processes within joints and alleviate pain
•Steroids, non-steroidal anti- inflammatory drugs (NSAID), and pain killers may be administered to reduce pain
•Acupuncture might also provide relief
•Your veterinarian has a lot of modalities to manage osteoarthritis in your pet 

What follow up care is needed?
•High impact exercise should be avoided
•Periodic check ups and laboratory tests are recommended to track response to therapy and the effect of medication on your pet
•OA is chronic and progressive, and its course is difficult to predict