Arthritis is a general term, there are actually a number of different types that can affect dogs. These include:
- Rheumatoid arthritis
- Infective arthritis
Osteoarthritis (OA), sometimes called degenerative joint disease (DJD), is the most prevalent and is the number one cause of chronic pain in dogs.
Osteoarthritis“A disorder of articular joints, characterised by degeneration and loss of articular cartilage (splitting and fragmentation) and the development of new bone on joint surfaces”
Without sounding like having just swallowed a text book, this basically means that any movable joint in a dog’s body can be affected by OA. Hips and elbows are two of the most common but other joints including shoulders, stifles (knees) and even the small interphalangeal joints of the toes can develop arthritis too.
Articular cartilage covers the ends of bones and allows them to glide smoothly against each other within a joint when a dog is moving around. This cartilage is a key component of OA. When the cartilage becomes worn or degraded with age then this can lead to inflammation and the joint becomes painful.
There are also a number of other soft tissue structures that make up a joint including tendons, ligaments and membranes which are all contained with the joint capsule. The synovial membrane or synovium is like the inner lining of a joint and produces synovial fluid. This fluid helps reduce friction between articular cartilages on the ends of the bones. All these structures interact within a joint to enable it to function properly and therefore any changes to these structures are also involved with the pathology of OA – the scientific causes and effects of the disease.
Many dogs often develop OA secondary to another disease or injury. For example hip or elbow dysplasia where the joint is not correctly formed causing abnormal wear to the cartilage and bone. Or a traumatic injury that has caused damage to a joint could lead to secondary arthritis developing later down the line.