Joint disease in cats has been historically underdiagnosed and should be considered in the differential diagnosis for cats presenting with vague signs of behavior change and decreased activity. Signs may include weight loss, depression, seeking seclusion, aggressive behavior, abnormal elimination habits, poor grooming habits, reduction in the ability to jump, or a stiff gait. The most common joints affected are the elbow and hip joints. Many cats have elbow osteophytes without clinical signs and no pain on manipulation of the joint; however, as the osteoarthritis progresses, the joint disease can progress and lameness develop. Most cats are affected bilaterally. Hip dysplasia has been identified in cats and can be a cause of joint pain, although many cats will have degenerative changes in their coxofemoral joints on radiographs without signs of discomfort or lameness. Conservative treatment of osteoarthritis aims to control pain associated with the joint degeneration and to slow progression of osteoarthritis. Strict activity restriction for the first month in acute cases of joint injury may be warranted so inflammation can subside. A nonsteroidal antiinflammatory drug such as meloxicam can control pain and improve quality of life for many cats. In cats with elbow osteoarthritis, arthroscopic removal of joint mice and debridement of medial coronoid defects can resolve the lameness; however, severe degenerative joint disease may not respond to this treatment or signs may recur as the osteoarthritis progresses. Serologic testing for tick-borne diseases and Bartonella species is recommended in cats with multiple joints affected and in which an underlying cause, such as trauma or hip dysplasia, has not been identified and infectious arthritis is suspected. Immune-mediated joint diseases (noninfectious) present with malaise, anorexia, lethargy, and varying degrees of lameness, stiff gait, or inactivity. Synovitis develops in multiple joints because of a type III hypersensitivity reaction. Treatment of immune-mediated arthropathies involves treating the underlying condition.

COMMENTARY: This article provides an excellent source of information about feline joint diseases in a nice, user-friendly overview. Appropriately, the author spends most of the discussion examining osteoarthritis and degenerative joint disease. There is a concise review of much of the literature about feline osteoarthritis and degenerative joint disease, including incidence and treatment. There is also a broad overview of inflammatory joint diseases seen in cats. This information provides an easy, quick reference to the clinician and will be very useful in a busy practice setting.—Steven Budsberg, DVM, BS, MS, Diplomate ACVS

Joint disease in cats. Baltzer W. NAVC PROC 2009, pp 998-1000.