Musculoskeletal Disorders (Congenital and Inherited) in Dogs

Each of these disorders causes different problems in certain parts of the body. For example, glycogenosis affects the muscles and liver; hip dysplasia affects the hips; muscular dystrophy (myopathy) affects the muscles; and osteochondrosis or osteochondritis dissecans affects the joints. Both glycogenosis and muscular dystrophy (myopathy) can be fatal without proper treatments.

There are many congenital and inherited musculoskeletal disorders in dogs. Some of the most common include glycogenosis, hip dysplasia, muscular dystrophy (myopathy), and osteochondrosis or osteochondritis dissecans. These abnormalities can cause moderate to severe deformities in dogs and, in some cases, may be fatal. These can be caused by a congenital defect, infections in the womb, or may be inherited. Some of the most commonly affected breeds include Poodles, Terriers, Retrievers, Hounds, Malamutes, and Dachshunds.

The symptoms are different for each type of musculoskeletal disorder. Some of the most commonly reported symptoms include:

Glycogenosis

• Appetite loss
• Weakness and lethargy
• Enlarged liver
• Collapse
• Inability to get up
• Death

Hip Dysplasia

• Painful hips
• Bunny hopping
• Difficulty standing
• Difficulty climbing stairs or jumping
• Lameness
• Inability to exercise
• Loss of muscle mass in hind limbs
• Decreased range of motion

Muscular Dystrophy (Myopathy)

• Drooling more than usual
• Swallowing difficulty
• Stiffness
• Weakness
• Enlarged tongue
• Loss of muscle mass
• Tremors
• Deformed limbs
• Flat feet
• Resistant to exercise

Osteochondrosis or Osteochondritis Dissecans

• Depression
• Reluctance to play
• Swollen joints
• Painful joints
• Grinding sound in the joints
• Stiffness
• Loss of muscle mass
• Lameness

Types

Glycogenosis is a genetic defect that causes a deficiency of glucose-6-phosphatase, which is needed to produce glucose. Too much glycogen builds up and causes chronic hypoglycemia (low blood sugar). There are four types, which include I-a, II, III, and IV. Unfortunately, they are all fatal.

Hip dysplasia is an inherited condition that causes a deformed ball and socket joint on one or both of the hips. This creates a loose joint, making the leg move around too much and causes severe pain.

Muscular dystrophy (myopathy) is a group of conditions that lead to the muscles to break down. The muscle cells thicken and cause a loss of muscle function.

Osteochondrosis or osteochondritis dissecans is a group of developmental diseases that result in the abnormal formulation of joint cartilage. The condition usually involves the elbow, hocks, stifle, and shoulders.

• Glycogenosis is an inherited disease that has four types I, which affects mostly toy breeds; II, is most common in Laplands; III, affects the German Shepherds and Retrievers; IV is more common in Spaniels
• Hip dysplasia can occur in almost any breed but is most often seen in large breed dogs like German Shepherds, St. Bernards, and Great Danes
• Muscular dystrophy (myopathy) is most common in Terriers, Bouviers, Spaniels, and Retrievers
• Osteochondrosis or osteochondritis dissecans is usually found in large breed dogs such as Great Danes, German Shepherds, Retrievers, and Collies

To diagnose glycogenosis, the veterinarian will do a physical examination and laboratory tests such as blood tests, glucose levels, and insulin production tests. Diagnosing hip dysplasia will also include the physical and blood tests as well as x-rays. Muscular dystrophy (myopathy) needs to be diagnosed by a special biopsy of muscle fibers, an electrical stimulation test, and an immunohistochemical staining test. A physical examination, blood tests, and x-rays are also important. Osteochondrosis or osteochondritis dissecans requires an extensive physical assessment, several x-rays, and a computed tomography (CT) scan.

Each of these musculoskeletal disorders has their own set of treatments.

Glycogenosis

This disorder is a progressive illness that causes increasing weakness until the dog cannot get up from a lying position. Short-term supportive treatments can be done such as a high carbohydrate diet and dextrose injections but there is no cure and most dogs die within a year.

Hip Dysplasia

Your veterinarian will prescribe a special diet, chondroitin and glucosamine supplements, and NSAIDS to help with the pain of this disease. In addition, there are several surgical methods that may help your dog depending on the severity of the dysplasia. Some of these methods include a total hip replacement, excision arthroplasty (for dogs under 40 pounds), triple pelvic osteotomy (for dogs under 10 months old), or juvenile pubic symphysiodesis (for dogs under 20 weeks old).

Muscular Dystrophy (Myopathy)

There is no specific treatment but glucocorticosteroids, surgery, and supportive therapy may help.

Osteochondrosis or Osteochondritis Dissecans

Medication (NSAIDS) and exercise restriction can be used if the damage is not severe. However, surgery is the most common treatment and will prevent any further pain in most cases. Arthrotomy and arthroscopy are two of the most effective procedures.

The prognosis for glycogenosis is grave since the disease is fatal within a year. Hip dysplasia patients have a good chance of recovery with treatment and exercise restrictions. Muscular dystrophy has a poor outcome in many cases and usually leads to heart disease, weakness, and debilitation. Osteochondrosis or osteochondritis dissecans is fair to good, depending on the severity of the condition and the age and health of your dog.