Osteoarthritis, also known as degenerative joint disease (DJD), is a condition that occurs when the cartilage at the ends of bones located within a joint begins to degenerate. Articular cartilage and synovial fluid act as a cushion between the bones during movement. As the cartilage weakens, bone on bone rubbing can occur, which can produce bone spurs (osteophytes) and bone and ligament or tendon injury. Osteoarthritis is typically an age-related disorder and evidence of joint degeneration can be observed on x-rays (radiographs) in 70-90% of older cats. Arthritis can also occur secondarily to injury or trauma to a joint. Obesity is a predisposing factor. Some breeds (Maine Coons, Himalayans, Persians and Scottish Folds) may have a genetic predisposition for arthritis development. Rarely, arthritis can be caused by infectious or inflammatory diseases.
Osteoarthritis can occur in any joint, but the hips, knees, elbows, and lower back (lumbosacral area) are most commonly affected in cats. Arthritis is a painful condition and lameness or limping can be observed. Many cats will only show subtle signs associated with arthritis including: decreased activity, difficulty walking or jumping, difficulty grooming, or constipation. In some cases, cats may not be able to access litter boxes readily and urination and defecation outside of the litter box may occur. Cats may become more withdrawn and less interactive with owners or other pets.
Although the effects of osteoarthritis are not reversible, there are many treatments available to alleviate the symptoms associated with osteoarthritis. Weight loss for overweight cats will help improve pressure placed upon the joints. Moving food and water dishes and litter boxes to a more accessible location (avoid the need for stairs or jumping) will improve access for your cat. Use low-sided litter boxes and add steps or ramps with non-slick surfaces to help with access to preferred sleeping sites.
Medications and Therapies for Osteoarthritis
Glucosamine/Chondroitin Sulfate: A dietary supplement used in both humans and animals to support cartilage health. It may take several weeks of supplementation before beneficial effects are observed. Studies testing the efficacy of glucosamine and chondroitin have been mixed and supplementation is often recommended to see if your cat will have a beneficial response.
Polysulfated Glycosaminoglycans (Adequan™): An injectable medication similar to glucosamine that supports cartilage health. It may take several weeks of supplementation before beneficial effects are observed.
Essential Fatty Acids: Omega-3 fatty acids found in fish oils can be used to reduce joint inflammation. It may take several weeks of supplementation before beneficial effects are observed.
Pain Medications (Buprenorphine, Tramadol): Opioid pain medications that offer pain relief but provide no anti-inflammatory effects.
Non-Steroidal Anti-Inflammatory drugs (NSAIDs): Help reduce joint inflammation and provide pain relief. Cats are extremely sensitive to most NSAIDs and overuse or use of the wrong drug can cause GI distress, and kidney or liver damage. Caution must be used in cats with known liver or kidneys disease. NSAID use should be closely monitored by your veterinarian.
Corticosteroids: Help reduce joint inflammation thereby alleviating some pain. High doses or long-term use of steroids has been associated with side effects such as diabetes mellitus, immune suppression, kidney insufficiency and rarely, heart failure. Steroid use should be closely monitored by your veterinarian.
Acupuncture: A technique that uses needle therapy at specific points on the body to reduce inflammation and stimulate natural endorphin (the body’s pain relief chemical) production. Studies in both humans and pets have shown beneficial responses in arthritic patients (increased mobility and activity).
Laser Therapy: A non-invasive technique that uses laser light to alter cells within the joint to alleviate pain and inflammation. Studies as to the efficacy of laser therapy are pending.