Canine hip Dysplasia is a very common degenerative joint disease seen in dogs. There are many misconceptions surrounding it. There are many things that we know about hip dysplasia in dogs as well as some things we don’t know about the disease.
What is Hip Dysplasia?
Hip dysplasia results from the abnormal development of the hip joint in the young dog. It may affect both hips and only one. It is brought about by the laxity of the muscles, connective tissue, and ligaments that should support the joint. Most dysplastic dogs are born with normal hips but due to genetics and possibly other factors, the soft tissues that surround the joint start to develop abnormally as the puppy grows. Dogs of all ages are subject to the symptoms of hip dysplasia and the resultant osteroarthritis. Puppies as young as five months will begin to show pain and discomfort during and after vigorous exercise. Some of the symptoms a puppy or dog can show are altered gate, resisting movements that require full extension or flexion of the rear legs. They may run with a “bunny hopping” gate. They will show signs of stiffness and pain in the rear legs after some activity. Some will limp and as the condition progresses the dogs will lose muscle tone.
Who gets hip dysplasia?
In dogs it is primarily a disease of large and giant breeds. Recently, I have seen it in smaller dogs such as, Jack Russell’s. It is primarily a disease of purebreds although it can happen in mixed breeds. German Shepherds, Golden Retrievers, Labrador Retrievers, Rottweillers, Great Danes, and St. Bernards appear to have a higher incidence of hip dysplasia. When you decide to choose one of these particular breeds it is a good idea to ask if the breeding pair have had a physical exam and radiographs. There are two different testing methods that can be performed. The traditional is OFA testing and the newer technique is the PennHip method. If the breeder says that they did not have their dogs examined and certified, and invents all types of excuses, don’t purchase puppies from that breeder. If the breeder says yes, ask to see the paper work on both dogs. Include in your questions if the breeder knew the breeding pairs parents and ask if they have been OFA or PennHip approved. If you can go three generations back with no hip dysplasia you are likely to purchase a puppy that will not get hip dysplasia. Most importantly, take your time purchasing your puppy. Research the breeders, ask your veterinarian for advice, and don’t be pressured into buying a puppy. In the long run you will be happier with the end results.
What are OFA and PennHip?
OFA; The method used by the Orthopedic Foundation for Animals. OFA has been the standard for many years. The OFA was established in 1966 and has become the world’s
Largest all-breed registry. Radiographic are taken by a local veterinarian
Under specific guidelines and are then submitted to the OFA for evaluation of hip dysplasia and certification of hip status. Since the accuracy of radiological diagnosis of hip dysplasia using the OFA technique increases after 24 months of age, the OFA requires that the dog be at least two years of age at the time the radiographs are taken. They also recommend that the evaluation should not be performed while the female is in heat. Three radiologists review the radiographs and a consensus score is assigned based on the animal’s hip conformation relative to other individuals of the same breed and age. Using a seven point scoring system, hips are scored as normal (excellent, good, fair), borderline dysplastic, or dysplastic (mild, moderate, severe). Dogs with hips scored as borderline or dysplastic are not eligible to receive OFA breeding numbers. The OFA will also provide preliminary evaluations (performed by one OFA radiologist) of dogs younger than 24 months of age to help breeders choose breeding stock
PennHIP: The diagnostic method used by the University of Pennsylvania Hip Improvement Program (PennHIP) uses distraction/compression radiographic views to more accurately identify and quantify joint laxity. Radiographs of the hip joints are taken with the dog under sedation. Two views are obtained with the hind limbs in neutral position to maximize join laxity. Weights and an external device are used to help push the head of the femur further into or away from the acetabulum. The amount of femoral head displacement (joint laxity) is qualified using a distraction index (Dl). The DI ranges from 0 to 1 and is calculated by measuring the distance the center of the femoral head moves laterally from the center of the acetabulum and dividing it by the radius of the femoral head. A DI of 0 indicates a very tight joint. A DI of 1 indicates complete luxation with little or no coverage of the femoral head. A hip with a distraction index of.6 is 60% luxated and is twice as lax as a hip with a DI OF .3. When the DI was compared the OFA scores for 65 dogs, all dogs scored as mildly, moderately, or severely dysplastic by the OFA method had a DI above .3. Hips with a DI below .3 rarely develop osteoarthritis visible on radiographs. Although hips with a DI above .3 are considered “degenerative joint disease susceptible” not all hips with a DI greater than .3 eventually develop osteoarthritis.
How is hip dysplasia treated?
There are several surgical procedures available depending on the age and the severity of the joint degeneration. The procedures are: Triple Pelvic Osteotomy (TPO), Total Hip Replacement, Femoral Head and Neck Excision, and Pectineal Myectomy. Medical treatment has greatly improved in the last several years thanks to the introduction and approval of several new drugs used to treat osteoarthritis. Through proper diet, exercise and supplemental glucosamine you can decrease the progression of degenerative joint disease but the looseness in the joint will not change significantly as a result of any supplement. For the best results, several of the following treatments must be instituted: weight management, proper exercise, Glucosamine and Chondroitin, buffered aspirin, Carprofen (Rimadyl), Polysulfated Glycosaminoglycan
(Adequan), vitamin C, and Corticosteroids. Discuss all treatments with your veterinarian and come up with the best solution for your dog.
- Hip Dysplasia is a widespread condition found mostly in larger breeds.
- There is a genetic link between parents and offspring.
- Osteoarthritis is the result of hip dysplasia.
- Surgical and medical treatments are encouraged to prevent and treat the resulting osteoarthritis.
- Best way to prevent hip dysplasia is through selection of offspring whose parents, grandparents and great grandparents have been certified to have excellent hips.
- Always consult your veterinarian for knowledge and treatment of hip dysplasia.