The dogs elbow is a complex joint made up of three bones the Humerus, Radius and Ulna. These bones need to fit together perfectly otherwise they are unable to articulate correctly and the joint develops abnormally. Elbow dysplasia is the most common cause or foreleg lameness and once abnormal development has  started secondary osteoarthritis is common. The principal cause lies in the genetic makeup of the dog but obesity, trauma to the joint, the dog's growth rate, diet and level of exercise can influence the severity of the condition. Any dogs that people are considering using for breeding should really be tested in order to reduce the number of dogs that suffer from this disease. Medium and large dogs tend to be more susceptible to elbow dysplasia although all breeds can be affected and it tends to be diagnosed before the age of two.

 

This disorder is normally classed as one of the following:-

 

Fragmented coronoid process (FCP) - This is the most common form of elbow dysplasia and occurs when the force of an abnormal joint causes microscopic stress fractures in the coronoid process of the ulna. These fractures of bones then become loose,  which irritates the joint further and destroys the surrounding cartilage causing the dog pain.

 

Ununited Anconeal Process (UAP) -  It occurs when a small bony projection called the anconeal process, grows separately and fails to unite and fuse with the ulna.

 

Osteochondrosis Dissecans (OCD) - is where cracks form in the articular cartilage from the condyle of the humerus. A loose flap of cartilage may then form or a piece may break off causing pain and inflammation. This normally occurs due to  a lack of blood flow in the subchondral bone.

 

Medial Compartment Disease (MSC) - also called to as Elbow Incongruity, is caused when the radius and ulna do not grow at the same rate. This causes misarticulation of the bones leading to the cartilage suffering more wear and tear than normal. This allows the bones to rub against each other causing inflammation and pain within the joint.