CHD is abnormal development of the hip joint. The hip joint consists of two parts; the acetabulum, which is the socket of the pelvis, and the femur that ends up as a ball that sitsdeeply in the socket. Like any joint in the body both of them are covered with a thin layer of cartilage that facilitates smooth movement of the joint. When the dog has hip dysplasia, the abnormalities of the ball and the socket do not have a perfect fit and this causes problems.
Who gets it?
Majority of the dogs diagnosed with CHD are medium to large breeds however small breeds and even cats can have it. Canine hip dysplasia is a congenital disease (the animal is born with it) but the genetic pattern is complicated and influenced by multiple genes. Environmental factors such as poor diet and strenuous exercise while young can contribute as well.
German Shepherds, Labradors, Golden Retrievers, St Bernard and Rottweilers are the breeds commonly suffering from this problem. The first symptoms are usually noticed between 6-18 months but sometimes even as early as 4 months.
What are the symptoms of CHD?
Lameness, pain, reluctance to exercise or jump, difficulties getting in the car or getting up are the most common symptoms that owners notice. Excessive hip movement, hind legs tucked under the body, steep pelvic angle or even “clicking” around back end when walking can also be noticed.
When examined most dogs will show pain on manipulation of hip joints, reduced movement in the hip joint, muscle loss in back legs and enlarged shoulder muscles due to putting more weight onto the front legs to alleviate the pain. Some dogs need heavy sedation to assess their condition further and minimise pain that can be significant. This is also a perfect opportunity to do additional tests such as Ortolani’s test (check the joint forinstability) since the dog is relaxed and pain free. X rays are often taken to examine the damage in the hip joint and the conformation of the joint. The x ray is used in the future as a reference point to monitor the advancement of the disease.
How can I help my pet?
Treatments can be divided into surgical and non surgical methods. Non surgical methods are often tried first. Pain relief, rest, limited exercise, Carthophen injections, food supplements, weight loss and quality food are most frequently attempted. Physiotherapy such as swimming or hydrotherapy can be beneficial as well.
Pain relief and Carthophen (pentosan) injections are medications most commonly used with good results. Carthophen injections provide good joint support and improve the quality of joint fluid, healing of the cartilage, reduce inflammation and improve blood supply to the cartilage. It is given as a course of 4 injections initially (one injection weekly) then as three monthly boosters. They can be used with other drugs and have no significant side effects. However, non-surgical methods are supportive treatment and only help in mild cases of CHD.
If your pet is one of the unlucky ones then surgical treatments may be the way to go.
Triple Pelvic Osteotomy
This option is available to young dogs up to 18 months without any signs of arthritic changes. It involves making three cuts through the pelvis to free the acetabulum. Once freed, it is repositioned and then special plates are used to change its angle so it fits better onto the “ball” (femur or thigh bone). Recovery period is around 4 months and lots of rest is needed.
Femoral Head Excision
This procedure is used in dogs less than 25 kg where the head of the femur (the ball) is removed and a false joint made of scar tissue is formed between the femur and the acetabulum (the socket). It is important to promote exercise as much as possible so that the connection between the bones gets strong. This procedure is cheaper than the first one and often effective.
Juvenile Pelvic Symphysiodesis
This procedure is suitable for dogs under 5 months of age and it consists of making a cut through the bottom of the pelvis in order to fuse this joint early which should improve contact between the femur and the acetabulum.
Total Hip Replacement
This is the best and most invasive procedure but offers good results. The femoral head and the acetabulum are fully replaced with an artificial joint. It is available in Australia but can be performed by a limited number of orthopaedic surgeons at present.
Prevention is the key
Many problems can be avoided by good management. Make sure you feed your dog a good quality and balanced diet. Spending a couple of dollars more can make all the difference. Avoid homemade diets since many are deficient in calcium or unbalanced in calcium phosphorus ratio. Also keeping your dog’s body weight in the right range is going to be beneficial.
Exercise your dog wisely by avoiding exercise with sudden acceleration, twisting and turning. Running on loose or slippery surface is not good idea either. Swimming is a great alternative to maintain muscle tone and keep joints tight. Buy your puppy from a respected breeder and ask if the parents were hip scored. Good hip score, although not a guarantee, can give you some reassurance that the dog should be hip dysplasia free.
DNA testing may become available and it could be more reliable then hip scoring.