Hip dysplasia is the malformation and degeneration of the hip joint, and is one of the most common joint diseases seen in dogs. Certain large breeds of dog such as the Labrador, German Shepherd, Golden Retriever and Rottweiler are more predisposed to hip dysplasia. What is Hip Dysplasia? Hip dysplasia, or HD, is a condition where the hip joint is predisposed to subluxate , the ball of the femur (top hind leg bone) does not sit properly in its socket in the pelvis. This interferes with the development of the joint so that the ball and socket become irregularly shaped, and puts pressure on the smooth cartilage surface of the joint, eventually causing degenerative joint disease (arthritis).What causes HD The disease is genetic, and large breeds of dog are more likely to develop hip dysplasia. The way the disease develops is also related to environmental factors such as early nutrition, with rapid weight gain not being desirable (see our article in this issue on Large Breed Puppy Nutrition). Too much early exercise and strain on the joints are also thought to be contributing factors. Signs of HD Early signs of disease are due to the looseness in the joint , severely affected pups as young as four months may have a swaying or “bunny-hopping” gait. Later signs are related to joint degeneration, with pain and reduced movement in the hips, resulting in reduced activity, difficulty in getting up, and reluctance to jump or climb stairs. The thigh muscles over the hip area may become visibly wasted. Purchasing a PuppyDogs that have HD should not be used for breeding. Intended breeding animals should come from proven HD-free lines, and are X-rayed at a year old, as before this time signs may still develop. These X-rays can be sent to the Hip Dysplasia Panel, who score the hips on several points. In breeds with a predisposition to the disease, it is prudent to buy puppies from parent animals with good hip scores. TreatmentTreatment will depend on the dogs size and age, the severity of the HD, and whether degenerative joint disease is present. HD is a very painful disease, and medical therapy centers on pain relief and anti-inflammatory medications. The “joint food ” type medications may also be useful, as they have a protective effect on the joint cartilage. Restricted exercise regimes are designed to suit the individual pet, with swimming recommended to maintain joint mobility while minimizing weight bearing. Weight control is very important, to reduce the load on the painful joints. Some pets may be candidates for various surgical procedures. In very young dogs before joint degeneration has occurred, hip surgery aimed at correcting the joint may be an option. In smaller older dogs with severe arthritis, the removal of the top of the femur can help to relieve pain in the joint. Total hip replacement is available from specialist veterinary centers for older pets with severe arthritis, if they are not responding to medical treatment. Ask your vet if you are interested in knowing more about treatment for hip dysplasia.