OCD - Osteochondrosis Dissecans

Definition of OCD

Osteochondritis dissecans, commonly known as OCD and osteochondrosis dissecans, is a disease of the cartilage that affects the joints in a dog's body. In any joint in the body two bones come together and movement is allowed between them. Where the two bones meet, an exceptionally smooth area of cartilage covers their surfaces. This acts as a cushion and protects the underlying bone. If anything disrupts this smooth cartilage surface, movement of the joint becomes painful. In a dog with OCD, this cartilage is damaged or grows abnormally. Instead of being attached to the bone it covers, it separates or cracks, causing great pain. In some cases, small pieces of cartilage break off and float free in the joint. These pieces of cartilage do not die, but rather continue to grow and increase in size. These are known as joint mice. Approximately 15% of all dogs will develop OCD.

Symptoms of OCD

 The symptoms are lameness in the affected limb. Some dogs have a barely noticeable limp and others are unable to bear any weight on the leg. The lameness tends to worsen after periods of exercise and improves after rest.
Seventy four percent of the cases of OCD occur in the shoulder joint, 11% in the elbow, and 4% in the hock. When it affects the front shoulder, a shortened forelimb stride may be noted due to reluctance to flex and extend the shoulder joint. Occasionally, the disease will affect both limbs simultaneously and the dog may be reluctant to move.

Noticeable Symptoms Include:

  • Lameness / Joint Pain

  • Unusual Walking Patterns

  • Lethargic Behavior / Limb Weakness

    • Diagnosis is based on history, physical exam, and radiographs (x-rays) can be easily done at Baker House Animal Hospital. On physical exam, we notice joint pain. For instance, most healthy dogs show no resistance when their shoulder joint is fully flexed and extended. However, if they have an OCD lesion in their shoulder, they may resist shoulder manipulation and may even cry out in pain when it is attempted. In addition, this flexion and extension of the shoulder joint may worsen the lameness.
    Radiographs of the affected joint are taken to confirm the diagnosis. The dog is often sedated so that full relaxation of the joint can be obtained. Several views of the affected joint and the healthy joint on the other side are taken for comparison. The separations of the cartilage or joint mice are often identified on radiographs.

    Causes of OCD

    The cause of OCD is considered to be multifactorial. Here are some of the known causes of OCD:
  • Joint Trauma

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  • Hereditary Factors

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  • Rapid Growth

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  • Restricted Blood Flow

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  • Nutrtion

    • Trauma, whether chronic or acute, may contribute to the formation of OCD lesions. Injury to the surface cartilage may lead to the separation of the cartilage from the bone or cause a decrease in blood supply that leads to cartilage flap formation.
    It appears that there is a hereditary link between parents and offspring and the formation of the disease. Certain breeds and genetic lines are much more likely to develop the disease. Careful screening of parents against this disease is recommended during the selection of all breeding stock.

    The disease usually occurs during periods of rapid growth. Therefore, it has been suggested that nutrition that creates rapid growth may lead to the increase in incidence of the disease. It has been recommended that animals that are susceptible to the disease be fed a diet that is lower in protein and fat, or that they are fed in a limited manner to allow steady even growth during the first year of life.

    Diet plays a major role in everything a dog does or is. An over fed pup who is carrying more weight than optimum has a greater statistical chance of developing OCD than a lean pup. That is not to say that you should underfeed a growing pup just to avoid skeletal deformities. That line of reasoning has been proven to be in error. Rather, be certain to feed high quality meat-based diets that do not have grain as their first ingredient. Diets with high protein and fat seem to be a better choice for dogs and cats than those diets high in carbohydrates like corn, wheat, soybean meal.

    Treatment of OCD

    Surgery is indicated in animals that show severe symptoms, in cases where large lesions are identified on radiographs, or when conservative treatments fail. The surgery is very straightforward. Usually the cartilage flap can be grasped with forceps and lifted away from the humerus. Some surgeons gently scrape the bed where the flap was situated in order to stimulate faster healing and some leave the area as it is. The joint is flushed again and closed with sutures. After surgery, rest for two weeks is recommended and then a gradual return to normal activity is encouraged. There is a very high success rate for surgery and most animals recover fully without any further problems. 

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