Arthritis is a complex condition involving inflammation of one or more joints. There are many causes of arthritis in pets. In most cases, the arthritis is a progressive degenerative disease that worsens with age.
The most common type of secondary arthritis is osteoarthritis (OA) which is also known as degenerative joint disease (DJD). Some common causes of secondary arthritis include obesity, hip dysplasia, cranial cruciate ligament rupture, and so forth. Other causes include joint infection, often as the result of bites (septic arthritis), or traumatic injury such as a car accident.