Canine Hip Dysplasia
Normal Hip Hip Dysplasia
Hip dysplasia is a syndrome that results from poor hip joint anatomy leading to bone and hip joint pain, known as osteoarthritis. The hip joint is formed by a round piece of bone, known as the head of the femur, that inserts into a bony pocket (the acetabulum) in the pelvis. When this bony head does not fit well into the pelvic hip joint socket, the joint is chronically unstable and hip dysplasia occurs. All breeds are susceptible to this condition although hip dysplasia is most prevalent in large breeds where it is an inherited trait. The exact mechanism of genetic expression is still unknown as it is under the influence of multiple genes. Environment, primarily feeding practices, can also influence the development of hip dysplasia. Studies in large breed dogs have shown that dogs fed 25% less food than those eating free choice (as much as they want) are less likely to develop dysplastic hips. For this reason puppies should be fed moderate amounts, usually twice daily, and we suggest that you give them 1o minutes to finish their meal, then pick up the bowl. This discourages over eating and the development of an excessive body mass that immature joints cannot support. The most critical time of development is from a few weeks to six months of age.
Once the joint begins to separate and instability occurs, degenerative changes follow in the cartilage and bone due to abnormal stresses. The degenerative changes are the cause of the pain and clinical signs associated with this disease. These clinical signs may come and go without any apparent reason but are often noticed after exercise.
Signs of hip dysplasia may begin as early as a few months of age or not develop until middle age, but most cases are diagnosed between 6 and 24 months of age. Owners may notice the dog is having difficulty rising, limping, or running with both hind legs together (bunny hopping). There may be pain or increased movement of the bones in the joint on physical exam. The clinical signs are important indicators of the disease, although the only way to definitely diagnose hip dysplasia is with a radiograph (x-ray) examination. If a dog is showing clinical signs and they are due to hip dysplasia it should be evident on an x-ray. However, if breeding your dog it is important to know that a dog will not be certified as hip dysplasia free by the Orthopedic Foundation for Animals until two years of age. For dogs at risk for this disease it is recommended that breeding animals are certified in this manner. Another radiographic method of hip evaluation is via PennHip a procedure for which Dr Herbert Hulls at Pet Care Veterinary Hospital is certified to perform. PennHIP incorporates an improved method for evaluating the integrity of the canine hip. It has great potential to lower the frequency of Canine Hip Dysplasia when used as a breeding selection criterion. The technique assesses the quality of the canine hip and quantitatively measures canine hip joint laxity.
There is a number of both medical and surgical treatment options available ranging from rest and anti-inflammatory drugs to total hip replacements. Each case is treated individually according to its severity, the age of the dog, and the desires of the owners. The ultimate goal is to reduce the pain associated with this potentially debilitating disease. Another goal is to decrease the incidence of this disease by controlled breeding. This is accomplished by breeding only dogs with normal hips and using a stud with a history of producing normal-hip progeny. Hip dysplasia is a devastating and crippling disease which deserves our efforts to reduce its frequency.
