Osteochondritis Dissecans (OCD) in Dogs

Welcome to Poodle Pulse! Today’s topic is Osteochondritis Dissecans (OCD)

Osteochondritis Dissecans (OCD) is a developmental orthopedic condition that affects the articular cartilage and subchondral bone in the joints. It typically occurs in young, fast-growing dogs and is most commonly seen in the shoulder, elbow, stifle (knee), and hock joints. The condition results from abnormal cartilage formation, leading to the development of a flap of cartilage that can become detached from the bone, causing inflammation, pain, and, in some cases, arthritis. Osteochondritis Dissecans (OCD) in Standard Poodles is relatively rare, but it can occur. The exact percentage of affected Standard Poodles is not widely documented, though estimates suggest that around 5% of standard poodles may be affected especially those observed with fast growth rates, particularly during their adolescent years.

Pathophysiology

OCD occurs when the cartilage in the joint does not form properly during growth. The affected cartilage becomes thickened, soft, and may break off or detach from the underlying bone. The detachment creates a flap that can cause pain, discomfort, and inflammation as it moves within the joint. Over time, this can lead to degenerative joint disease or arthritis.

Key Factors Influencing OCD Development

1. Genetics

• • Genetic Predisposition: OCD likely has a genetic component. Research has shown that certain breeds are more susceptible to developing OCD, especially those with rapid growth patterns and larger body sizes. For example, large and giant breeds such as Labrador Retrievers, Golden Retrievers, German Shepherds, and Standard Poodles are at higher risk.
    • Polygenic Nature: OCD is likely to be polygenic, meaning it is influenced by multiple genes rather than a single gene. Environmental factors like nutrition, exercise, and growth rate can also interact with genetic predisposition to increase the likelihood of developing OCD.
    • At present, there are no commercially available genetic tests that can directly identify the specific gene or mutation responsible for OCD in dogs. However, studies have shown that the condition is heritable in several large and giant dog breeds, meaning that it tends to run in families. This has led to a focus on selective breeding practices to reduce the incidence of OCD in affected breeds, but it remains challenging to pinpoint a single genetic marker for the condition.
    • Ongoing Research: Research into the genetics of OCD is ongoing, and some studies are investigating the relationship between cartilage formation genes and joint development. However, no conclusive results have yet led to the identification of a specific gene or genetic marker that can be tested for at this time.
    • Selective breeding has been recommended to reduce the occurrence of OCD in future generations. Even though a genetic test for OCD is not yet available, breeders can still reduce the incidence of the condition by focusing on selective breeding practices that prioritize joint health. This includes:
      • Hip certification (e.g., OFA or PennHIP) to ensure that breeding dogs do not have joint abnormalities.
      • Breeding from lines that have a history of fewer OCD cases or whose offspring have shown good joint health.
      • Avoiding breeding dogs from families with a history of OCD or with known orthopedic issues.

2. Nutrition

• • Nutritional Factors: The development of OCD is influenced by dietary factors, especially in growing puppies. Excessive protein intake, imbalanced calcium-to-phosphorus ratios, and high-energy diets can promote excessive bone growth and abnormal cartilage development, increasing the risk of OCD.
    • Calcium Overload: Rapid bone growth, driven by an excess of calcium in the diet, can lead to abnormal cartilage formation. High calcium levels are often seen in puppies fed too much puppy food formulated for rapid growth, particularly in large-breed puppies.
    • Calcium and Phosphorus Imbalance: The optimal ratio of calcium to phosphorus in a puppy’s diet is around 1.2:1 to 1.4:1. An improper balance can interfere with bone and cartilage development, contributing to OCD.
    • Vitamin D: Vitamin D helps regulate calcium absorption and bone formation. Both insufficient and excessive Vitamin D can impair bone and cartilage health, contributing to OCD.
    • Relevant Study: A study published in the Journal of the American Veterinary Medical Association (JAVMA) by Case et al. (2018) highlighted the impact of calcium imbalances on the development of skeletal diseases, including OCD, in growing puppies. (Case et al., 2018)

3. Exercise and Environment

• • Exercise and Joint Stress: High-impact, repetitive exercise during the rapid growth phase can contribute to the development of OCD. Overexercising puppies, particularly large and giant breeds, can place excessive stress on immature joints and disrupt normal cartilage development.
    • Excessive Exercise: Overexertion or excessive activity in growing puppies, particularly in large and giant breeds, can contribute to joint injury and increase the likelihood of OCD. Puppies with growing bones and developing cartilage may not yet have the structural maturity to handle intense physical activities. For example, jumping, running, or engaging in activities that put repetitive strain on the joints (like playing on hard surfaces) can increase the risk of joint injuries, which may lead to OCD.
      • The stress of rapid growth in combination with intense exercise can contribute to abnormal cartilage development and tears. This is especially true when the growth plates are still open, and the bones are soft and not fully developed to handle such loads.
      • Sudden changes in exercise intensity or transitioning from sedentary to more intense physical activity can put an immense strain on the joints and increase the risk of cartilage damage.
    • Joint Trauma
      • Acute Injury: Direct trauma to the joint, such as a sudden impact, twist, or fall, can cause cartilage damage. This can contribute to the development of OCD, particularly in puppies or dogs still undergoing joint development. For example, an impact injury during a high-energy activity or an accident (such as a fall or collision) can damage the cartilage or the underlying bone, potentially leading to the development of an OCD lesion.
      • Chronic Stress: Repetitive, low-grade trauma, or microtrauma, over time can stress the cartilage and underlying bone. This repetitive injury often occurs in dogs that are highly active, such as those involved in sports or agility, or in working dogs that are subject to repeated physical exertion. The repeated strain can weaken cartilage and bones, leading to the detachment of cartilage in certain areas.
    • Environmental Factors: The environmental aspects of exercise, including the surface type (hard surfaces like concrete) and the nature of activity (sudden, jerky movements vs. controlled exercise), can exacerbate joint stress and contribute to the development of OCD.
    • Relevant Study: In a study by Smith et al. (2002) in the Journal of Small Animal Practice, they found that rapid, high-impact activities (e.g., running on hard surfaces) before joint closure in young dogs contributed significantly to the development of OCD. (Smith et al., 2002)

4. Growth Rate and Size

• • Rapid Growth: The likelihood of developing OCD is higher in dogs that undergo rapid growth in early life, especially large and giant breeds. Rapid weight gain and disproportionate growth can place abnormal stress on the growing bones and joints, increasing the risk of the condition.
    • Standard Poodles: While generally not as prone to OCD as the largest breeds, Standard Poodles (like many medium to large breeds) can still develop OCD, particularly when subjected to rapid growth during their first year.
    • Joint Size: Larger breeds with larger joints may also be more susceptible because their joints experience more force, making them more prone to abnormal cartilage development.

5. Gender

• • Sex Differences: Male dogs tend to be at higher risk for developing OCD than females. This is especially true in certain large and giant breeds, though this may be influenced by growth rates and hormonal factors.

Osteochondritis Dissecans (OCD) in dogs is influenced by multiple factors, including genetics, nutrition, exercise, and growth rate. Genetics play a significant role, especially in large breeds, and certain nutritional imbalances can exacerbate the risk. Excessive exercise, particularly in young dogs, and high-energy diets also contribute to the development of OCD. A responsible approach to breeding, careful management of diet and exercise, and monitoring a dog’s growth can help reduce the incidence of OCD in vulnerable breeds.

References:

• Lui, R. H., et al. (2016). Osteochondritis dissecans in dogs: A review of the literature. Journal of Veterinary Internal Medicine. Link to article
• Case, L. P., et al. (2018). Nutritional factors in skeletal development and disease in puppies. Journal of the American Veterinary Medical Association. Link to article
• Smith, G. K., et al. (2002). The influence of exercise on the development of joint diseases in growing dogs. Journal of Small Animal Practice. Link to article