Elbow Dysplasia

Dog by a wood door

There can be no worse or sadder diagnosis for a puppy or young dog than limb and joint defects. Puppies and young dogs love running, jumping, playing, and rolling, but joint diseases such as elbow dysplasia can prevent them from enjoying these activities. Elbow dysplasia is a developmental disease of the canine elbow, encompassing a range of joint abnormalities that share a common anatomical location (the elbow) and developmental origin.

Before describing the different conditions grouped under the term “elbow dysplasia,” it may be useful to first recall the basic anatomy of the canine elbow joint, as well as the bone components that may be involved in these conditions. The canine elbow joint consists of three joints:

  1. The humeroradial joint, between the distal (lower) end of the humerus and the proximal (upper) end of the radius.
  2. The humeroulnar joint, between the distal end of the humerus and the proximal end of the ulna.
  3. The radioulnar joint, between the proximal ends of the radius and ulna.

Three bone structures that participate in forming the elbow joint can be involved in elbow dysplasia:

  1. The anconeal process of the ulna, which is the most cranial (front) aspect of the ulna that articulates with the humerus.
  2. The humeral condyle, the distal part of the humerus that articulates with both the radius and ulna.
  3. The coronoid process of the ulna, which makes up most of the joint surface contact between the humerus and the ulna.

A developmental abnormality of any of these bone structures can lead to elbow dysplasia. The conditions grouped under this term include:

  • An ununited anconeal process, where the anconeal process fails to unite with the rest of the ulna beyond 20 weeks of age.
  • Osteochondrosis dissecans of the humeral condyle, a failure of ossification (hardening) of the articular cartilage covering the humeral condyle, resulting in abnormal thickening and separation between the cartilage and underlying bone.
  • Fragmentation of the coronoid process, where the ulnar coronoid process has multiple fragments or, more commonly, a single fragment. The latter two conditions often occur simultaneously.

Treating Elbow Dysplasia in Dogs

All these conditions have a strong genetic component, as demonstrated by the high incidence of ununited anconeal process in German Shepherds and the higher occurrence of osteochondrosis dissecans and coronoid process fragmentation in breeds such as Labrador Retrievers, Golden Retrievers, and Newfoundlands. Other factors that can increase the risk of elbow dysplasia—particularly osteochondrosis dissecans—include diet and growth rates. The risk is higher in large-breed dogs that are overfed high-energy, protein-rich diets during their juvenile growth period or given excessive calcium supplementation. Hormonal imbalances, such as the predilection of males to develop osteochondrosis dissecans, also play a role.

Regardless of the cause, the clinical signs of elbow dysplasia typically emerge between 4 and 7 months of age (4 to 12 months for ununited anconeal process). The age at diagnosis usually ranges from 6 to 18 months. Symptoms common to all three conditions include generalized forelimb muscle atrophy, swelling of the elbow joint with increased fluid and sometimes bone production, decreased range of motion with pain, and varying degrees of lameness. Lameness may be intermittent, exacerbated by heavy activity, or more apparent after rest. In severe cases of bilateral disease, dogs may lie in a recumbent position and be reluctant to stand or move.

The treatment for elbow dysplasia can be either medical or surgical, depending on the severity of the condition, the general health of the dog, the dog’s ability to cooperate, and the owner’s financial situation. While surgery aims to physically remodel the affected joint structures through various techniques, medical treatment is more conservative and similar to that for osteoarthritis. Medical treatment includes body weight control, exercise restriction, and the use of analgesics like nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, phenylbutazone, carprofen, and etodolac. Both medical and surgical approaches have been shown to provide good clinical outcomes, though results typically take time to become apparent.

Veterinarians generally recommend against breeding affected dogs, their parents, siblings, or offspring. While this advice may be frustrating to some owners, the rationale is simple and clear: elbow dysplasia, especially osteochondrosis of the humeral condyle, is a highly heritable condition. Although the condition can be managed with proper treatment, the affected dog will always remain a carrier and can pass the condition on to future generations. Therefore, the most effective way to prevent the spread of elbow dysplasia is to avoid breeding affected individuals or their relatives. This is not human selection; it reflects the natural process where, in nature, most animals with birth defects are unable to breed.

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