The hip joint is the attachment of the hind leg to the body and is roughly composed by the head of the femur (leg) and the acetabulum (pelvis). In a normal joint the head of the femur freely within the acetabulum. To facilitate movement and strengthen the joint bones are shaped to perfectly match each and the two bones are held together by a strong ligament. Also, the joint capsule, encircles the two bones providing further stability.
Dysplasia refers to an abnormality in development so that, as dogs grow, their hip joints become instable. Its appearance in dogs is determined by an interaction of genetic and environmental factors and there is a complicated pattern of inheritance with multiple genes involved.
It commonly affects larger breeds of dogs, like German Shepherds, Rottweilers, retrievers, Great Danes and St. Bernards. However, dogs of all breeds and sizes are susceptible to this condition.
Because hip dysplasia is caused by an inherited defect, there is no medication that can prevent its development and each case is different, depending on individual related factors like caloric intake, level of exercise, pelvis muscle mass. Hip dysplasia can begin to develop in puppies but only be notorious in geriatric years and it is possible to see dogs with only mild visible changes that have severe signs of pain, as well as animals with marked changes that are able to go along with their lives with minimum complaints.
Symptoms depend on the degree if joint inflammation and for how long the disease is progressing. They include lameness that is often worsen by exercise, altered gait (like a bunny hop), narrow stance in the hind legs, reluctance to walk and radiographic signs of articular luxation and osteoarthritis.
To diagnose hip dysplasia your veterinarian will perform a complete physical exam on your dog, including a blood chemical profile, a complete blood count (that may reveal values associated with inflammation due to joint disease), an electrolyte panel and a urinalysis. A thorough history of your dog’s health, onset of symptoms, and any possible injury that may have contributed to the situation is also very important. Any information you have on your dog’s parentage will be helpful as well.
X-rays are crucial for visualizing the signs of hip dysplasia and is the only way to categorize the degree of dysplasia. An anesthesia is required because the procedure may be painful and the hip joint has to be stretched all the way back. In Portugal there are 5 main degrees of hip dysplasia: A and B for the animals without radiographic signs; C, D and E for animals with light, moderate and severe dysplasia, respectively. The radiographic studies for the diagnosis of this condition should be performed in animals with 12 months for the medium sized breeds, and 18 months for larger breeds. After 5 years of age it is not advisable to make a diagnosis following the radiographic changes because there may be other age related processes that may mask or mimic the hip dysplasia changes.
There is no cure for this condition but there is surgical treatment. The recession of the head of the femur solves the pain by eliminating the contact between bones. The animals then have to be stimulated to reinforce the pelvis muscles in order to support the affected limb properly. Medication like glucosaminoglycans, antioxidants and condroprotectives may slow the progression of the disease and improve the clinical signs. Some animals benefit from anti-inflammatory drugs for briefs periods of time.
If you have a dog suffering from this condition remember to always assess his pain status and promote an healthy life with controlled exercise and maintenance of the ideal weight.
Never breed animals that fit the C, D and E categories of dysplasia.
