Canine elbow dysplasia (ED) is a condition involving multiple developmental abnormalities of the elbow joint. The elbow joint is a complex joint made up of 3 bones (radius, ulna, and humerus) (figure 1). If the 3 bones do not fit together perfectly due to growth abnormalities, abnormal weight distribution on areas of the joint occur causing pain, lameness, and the development of arthritis. Elbow dysplasia is a disease that encompasses several conditions grouped into medial compartment disease (fragmented coronoid process (FCP), osteochondrosis (OCD), joint incongruity, and cartilage anomaly) and ununited anconeal process (UAP). The cause of ED in dogs remains unclear. There are a number of theories as to the exact cause of the disease that include genetics, defects in cartilage growth, trauma, diet, and so on. It is most commonly suspected this is a multifactorial disease in which causes the growth disturbances, (Figure 1).
Elbow dysplasia is an inherited condition that can occur in most dog breeds but is most commonly seen in large to giant breed dogs. It has been noted to affect both elbows in up to 80% of patients. Bernese Mountain Dogs, German Shepherds, and Golden retrievers among others are predisposed to UAP while Labrador retrievers, German Shepherds, and Golden retrievers have an increased predilection among other breeds for developing medial compartment disease.
Unfortunately, once the elbow joint has been damaged through either cartilage loss, medial compartment disease or an ununited anconeal process, inflammation and further cartilage damage occurs. Ultimately this causes progressive arthritis of the elbow joint leading to pain and loss of function.