What is osteochondrosis?
Osteochondrosis is a disease of the cartilage found in young growing dogs. It is associated with the abnormal attachment of the cartilage to bone. It can happen in different joints but most often is found in the shoulder, elbow, knee or tarsal joints in young dogs of large breeds.
The abnormal growth triggers a thickening of the cartilage, then an fissure (or breakage) and in some cases the formation of a cartilage flap (small detached piece) that will be loose within the joint. The medical term used is osteochondritis dissecans.
Animation of the normal shoulder anatomy in the dog
Animation of the osteochondritis dissecans in the dog
What are the dogs affected?
Shoulder osteochondrosis affects young dogs (between 4 and 8 months of age) of large sizes and fast growth. In other words, dogs that will weigh over 20 kg when adults. It affects generally both shoulders.
How does osteochondrosis develop?
During growth, bone is producing cartilage that is progressively replaced by bone substance. A normal bone's growth depends on the balance between the production of new cartilage and the concomitant production of new bone replacing this cartilage tissue.
Osteochondrosis (or chondrodystrophy) is a defect of the turn-over of cartilage tissue into bone. Consequently the affected cartilage tissue is thickening in the area of the defect. The process may stop with growth but in most cases the affection will develop into more severe lesions and fissures of the cartilage creating 'flaps' or free segments of cartilage tissues floating within the joint. At that stage it is called 'osteochondritis dissecans' because of the dissociation of the cartilage tissue. The flap will generate pain and rubbing within the joint with subsequently a secondary arthrosis development.
Image of a cartilage fragment from a dog's shoulder operated for OD:
What is the cause of OD?
There are multiple causes : it is a multi-factorial disorder. The rate of growth, the gain of weight, are predisposing factors in large dogs. There are some genetic predisposition, possibly nutritional and traumatic factors associated with the incidence of the disorder.
How to diagnosis the disease?
Diagnosis is based on imaging of the joint (radiographs). Both shoulders should be radiographed.
Images of shoulder's radiographs from a dog with OCD:
What is the treatment?
The treatment is surgical. Anti-inflammatory drugs may be used for some time prior to surgery. Rest and progressive return to normal exercise is the usual post-operative management. Prognosis is good and dogs return to normal.
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