Osteoarthritis affects around 1 in 5 dogs and is a degenerative and permanent joint disease. It is caused by inflammation and deterioration of articular cartilage, subchondral bone and soft tissue around the joint.  As cartilage has no nerve endings, the dog is unaware of its degeneration until it starts to become thin reducing its cushioning impact within the joint. In severe cases where the cartilage is very thin or worn away the bones start to rub against each other causing pain, joint inflammation and eventually bone changes. Bony projections called osteophytes can also form on the bone close to the joint, which in turn causes swelling and increased synovial fluid resulting in added pain and inflammation.

 

Osteoarthritis can be caused through trauma, congenital defects present at birth, abnormal wear and tear on the joints and obesity. It can also be a result of other conditions such as Hip dysplasia, Patella luxation and Osteochondrosis. Dogs that are diabetic, had prolonged steroid treatment or Hyperlaxity (excessive looseness of joints) tend to be at high risk of developing Osteoarthritis.