What is Osteochondrosis (OC) and Osteochondritis Dissecans (OCD)?
Osteochondrosis Dissecans (OCD) is a pathological condition that occurs in border collies (as well as several other breeds). During normal bone growth cartilage is replaced by bone (a process called endochondral ossification). In dogs with OCD, the process of cartilage being replaced by bone does not occur normally resulting in excessive cartilage growth in the joint. The thickened cartilage can then break loose causing a flap (see pictures below). OCD most commonly occurs in the shoulders, but can also be found in the stifle, elbow and hock. It occurs more commonly in males than females. Typical age of onset is 4 months to one year.
Causes
Research has not yet identified a definitive cause for OC/OCD. Because OC/OCD is more common in certain breeds and lines, it does appear to have a hereditary component. It is still unclear whether this is direct or indirect. Research into the genetic component of OC/OCD in border collies is currently underway at the University of Helsinki. See the Research page for more information about how to participate in this studyz.
Environmental factors may also play a role. Rapid growth and trauma are known factors that influence the development of symptoms of OCD. Some studies have pointed to nutrition (high protein and calcium) as a contributing factor.
It is a most likely has multiple causes, with no single factor being responsible for the development of OC/OCD lesions. (1) For example, a dog has a genetic predisposition to develop OC/OCD lesions and environmental factors (trauma, nutrition, etc) influence the development of symptoms leading to the diagnosis.
Environmental factors may also play a role. Rapid growth and trauma are known factors that influence the development of symptoms of OCD. Some studies have pointed to nutrition (high protein and calcium) as a contributing factor.
It is a most likely has multiple causes, with no single factor being responsible for the development of OC/OCD lesions. (1) For example, a dog has a genetic predisposition to develop OC/OCD lesions and environmental factors (trauma, nutrition, etc) influence the development of symptoms leading to the diagnosis.
Diagnosis
Most dogs with OCD present with lameness that is worse after exercise. Properly positioned shoulder films typically reveal a flattened area on the humeral head of the shoulder. It is possible to have osteochondronsis (OC) without the dissecans (or cartilage flap). The radiographs shown below are from a normal dog (left) and a dog with an OC lesion (right).
The dog with the OC lesion was taken to an orthopedic specialist for an exam and radiographs because a littermate was diagnosed with OCD. The dog showed no signs of lameness. This is because a dog that does not have a cartilage flap, does not have any underlying bone exposed to the joint fluid. The joint fluid coming into contact with the underlying bone is what is believed to cause the pain associated with the condition.
Treatment
OC/OCD lesions can be treated non surgically or surgically. Surgical treatment is generally recommended over non surgical treatment. The majority of dogs with shoulder OCD that have the flap removed surgically have successful recoveries. More conservative treatment of dogs with clinical lameness is typically unsuccessful.
Non-Surgical Treatments Non surgical management of OCD includes restricted activity, use of non-steroidal anti-inflammatory drugs (NSAIDs) or steroids to reduce inflammation, pain medications, use of polysulfated glycosaminoglycans (such as Adequan) and the addition of supplements to support joint health. Changing the dog's diet to a food that is lower in protein/calcium and maintaining a lean body condition are also commonly recommended. More recently platelet rich plasma (PRP) therapy and Class IV laser therapy have been used by some orthopedic veterinarians to treat OCD. Both treatments may help reduce arthritic changes, but more clinical studies need to be performed to assess the effectiveness of such treatments. Surgical Treatments Two different surgical treatments of OCD are available: the standard arthrotomy and arthroscopic surgery. Surgical treatment is the treatment of choice and the majority of dogs that undergo surgical correction of OCD in the shoulder recover to be fully functional dogs. When surgical treatment is combined with post-operative rehabilitation, the prognosis is typically good to excellent. |
Videos used with permission of Colorado Canine Orthopedics & Rehab
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Sources
1. B. Ytrehus, C. S. Carlson, and S. Ekman
Etiology and Pathogenesis of Osteochondrosis
Vet Pathol July 2007 44: 429-448, doi:10.1354/vp.44-4-429
Abstract Full Text (PDF)