Osteoarthritis

Osteoarthritis is the most common form of arthritis in dogs and cats. In dogs, osteoarthritis is nearly always secondary to some other primary disorder of a joint such as dysplasia, instability, or joint injury such as a fracture. As such, it is often important to find out what the primary cause of the osteoarthritis is and this might involve clinical examination, diagnostic imaging (X-rays, CT scan, MRI scan) or arthroscopy (key-hole surgery).

Osteoarthritis affects all aspects of a synovial joint. Joints surfaces are lined with a very thin tissue called articular cartilage and this is gradually eroded during the process of osteoarthritis. The joint is surrounded by a soft tissue capsule which is lined by a reactive tissue called synovium. The synovium becomes inflamed during osteoarthritis and most of the pain in osteoarthritis in fact comes from the synovium. The bones either side of the joint also change in osteoarthritis: the bone beneath the cartilage can becomes sclerotic (hard and dense) and new bony growths (osteophytes) can appear at the margins of the joint. When cartilage becomes fully eroded, the bone underneath can become exposed and this can cause more severe pain.

Assessing the severity of osteoarthritis

Sometimes, the osteoarthritis has advanced to the point where it is the main cause of pain from a joint. In such circumstances, there are different ways to manage the problem:

Conservative management

Conservative management involves a combination of measures designed to reduce pain and improve mobility. Things to consider include:

Optimising bodyweight and avoiding overweight and obesity

Using controlled exercise programmes, and possibly hydrotherapy and physiotherapy

Environmental adaptations – avoiding slippery floors, using ramps.

Medication – there are various types of medication that can be used for osteoarthritis and careful consideration of the available options is important to weigh up the benefits and possible risks. Medication may be required long-term, and so careful monitoring under veterinary supervision is important.

Surgery – when osteoarthritis becomes so severe that medication is not sufficient to maintain quality of life, sometimes surgery is considered. Again, this needs careful consideration and the benefits and risks need to be carefully discussed. Sometimes, in the right circumstances, surgery is performed as an alternative to medical management. Surgery may involve total joint replacement, such a total hip replacement, fusing of the joint (arthrodesis), or removal of part of the joint (excision arthroplasty).

Total hip replacement is a very successful operation and can return a dog to excellent mobility without ongoing pain. However, careful counselling with an experienced surgeon is necessary to weigh up the benefits versus the risks. You can read more about hip replacement on our ‘hip‘ page.