Osteoarthritis, also known as degenerative joint disease (DJD), is the progressive and permanent long-term deterioration of cartilage surrounding the joints.
Arthritis is the medical term for inflammation of the joints, while osteoarthritisis is the term referring to a form of chronic joint inflammation caused by deterioration of joint cartilage. Older dogs and younger dogs with genetic defects are at the highest risk.
DJD is a painful and debilitating disease and the initial symptoms vary. A dog may exhibit a decreased level of activity, occasional lameness, and a stiff gait that worsens with exercise. These symptoms may increase with exercise, long periods of inactivity or in cold weather.
There is no known cause for primary DJD. However, there are a wide variety of causes for secondary DJD, such as trauma, abnormal wear on joints and cartilage, obesity, or a congenital defect present at birth such as an improperly formed hip (hip dysplasia).
Secondary DJD may include abnormal development of the hip or elbow (hip or elbow dysplasia), dislocation of the kneecap or shoulder, and osteochondritis dissecans (OCD), a condition in which the bone and cartilage develop abnormally so that a flap of cartilage develops within the joint.
Obesity is another factor for DJD, as it increases stress on joints. In addition, dogs with disorders such as diabetes, prolonged steroid treatment, and hyperlaxity (an excessive looseness of the joints) may also be at higher risk for DJD.