Dyschondroplasia in Dogs

Dyschondroplasia is said to be a multifactorial joint disorder most commonly seen on the shoulder and elbow joints in large to giant breed dogs. This is because it is believed that these larger breeds tend to grow at a faster rate, thus predisposing them to this degenerative disorder. 

Dyschondroplasia is most commonly seen in dog breeds such as Labradors, Great Danes, Basset Hounds, Poodles, Scottish Terriers and Alaskan Malamutes.

Dyschondroplasia (also known as osteochondrosis) is a disease of the cartilage and bones. Most common around joints, new-forming cartilage in young dogs fails to properly ossify into bone resulting in retained cartilage that can eventually lead to articular collapse. In some cases, a flap may form as a result of the abnormal thickening of the cartilage; this flap may break off and get stuck in between the joint capsule resulting in severe lameness and pain.

Due to its gradual effect on joints common symptoms include:

• Lameness on affected leg
• Muscle atrophy due to poor blood supply
• Secondary osteoarthritis 
• Likely an inability to flex or extend joint
• Pain and inflammation around joint.
• Inability to climb, jump, run
• Limping and unable to bear weight on the affected joint
• Stiffness on the affected joint
• Dog may be unable to exercise
• Lethargy
• Difficulty sitting or standing.

Types

• Shoulder Dyschondroplasia
• Elbow Dyschondroplasia
• Stifle Dyschondroplasia
• Hock Dyschondroplasia

There are multiple factors that may predispose a dog to dyschondroplasia. Some of these include:

• Breed lineage and genetics (heredity)
• Age (most common in large breeds between 6 to 9 months of age)
• Rapid growth during puppy phase
• Trauma
• Hormonal imbalance
• Inadequate nutrition 
• Sex (often this disease is more common in male dogs than females)

These factors result in cartilage not ossifying completely which may lead to the forming cartilage splitting off into fragments. These fragments termed “joint mice” rest in the joint capsule and space and so can lead to inflammation and pain of the bone and joint.

Veterinarians will first conduct a clinical exam of the dog’s joint movements seen as flexion and extension, structure, gait and posture. Upon physical examination, muscle atrophy and/or inflammation of the joint may be noticed. This will result in your veterinarian recommending X-rays and CT scans to locate the lesions and its severity. Radiographs may be taken on both legs even if only one leg shows signs of lameness, this is because dyschondroplasia can be seen on the other side as well but may not be as severe. Another less commonly used diagnostic technique is placing a camera in the joint; this is often referred to as an arthroscopic examination.

Surgery is the current method of treatment for dyschondroplasia. For elbow dyschondroplasia there are 3 types of surgical procedures done; the first is the removal of fragments of cartilage that may be trapped within the joint. A second procedure, referred to as incongruency, involves the reshaping and repositioning on the elbow joint to decrease pressure on the bone. Thirdly is a salvage procedure which is rare but often involves a TER (total elbow replacement). Surgery tends to be used for more severe or difficult cases; however, arthroscopy is another minimally invasive procedure which can be used to treat dyschondroplasia.

Depending on the affected joint and severity recovery time may be variable.

Dogs with mild shoulder dyschondroplasia often tend to recover fast and are able to get back into regular exercise routines. However, intensive physical activity may lead to occasional lameness.

Dyschondroplasia of the elbow joint involves a lot more management of the dog’s lifestyle by controlling exercise routine and weight. Veterinarians may suggest that post recovery, owners should consider restricting their pet’s diet, thereby preventing unnecessary weight gain which may cause unwanted pressure on the joint. Some veterinarians may recommend other forms of therapy such as hydrotherapy or swimming after 6 weeks post-operation.

Post surgery, your veterinarian may provide your pet with a dose of NSAIDs to alleviate pain and decrease inflammation. This may be in the form of aspirin (10 mg/kg), carprofen (2.2mg/kg) or tepoxalin (10 mg/kg/ day). Your veterinarian may recommend that walks may be restricted to less than 10 minutes and suggest the animal go on rest for 4 to 8 weeks, depending on severity of the situation.  A dose of polysulfated glycosaminoglycan (4.4 mg/kg) may be given twice for four weeks in order to prevent the cartilage from further degenerating.

It has been speculated that owners should consider reducing the energy and calcium intake in the dog's diet as studies suggest this may decrease the chances of the dog developing further orthopedic disease.

Post-surgery and recovery most dogs are able to live relatively normal lives however they may develop occasional stiffness and lameness in their joints as they age. And so exercise should not exceed the minimum requirements.