Hip Dysplasia

Posted by admin on Jan 27, 2012 in Health | 0 comments

Introduction
“Ranger has been running funny and has had trouble getting to his feet after a nap,” Sally told Dr. Jones when she brought the two-year-old family pet for his annual checkup. She described Ranger’s bunny-hopping gait and reluctance to climb stairs; after a thorough physical exam, Dr. Jones suggested hip x-rays for the big dog.
The x-rays confirmed the suspicions: Ranger had mild hip dysplasia, a malformation of the hip joints that causes arthritis. Dr. Jones outlined the options: surgery, drug therapy, an exercise regime, nutritional therapy, chiropractic treatment, or acupuncture. Surgery was not indicated in Ranger’s case, Dr. Jones said, but the other therapies could be used in combination to reduce the pain and inflammation and keep the dog comfortable.

The diagnosis
“Your dog has hip dysplasia.” A dreaded diagnosis that confirms an owner’s worst fears, these words conjure up feelings of guilt (why did I buy my puppy from a pet store?) or betrayal (I thought mixed breed dogs were healthier than purebreds, or I thought Bosco’s breeder certified her stock against genetic diseases). But neither response is productive or appropriate. The job now is to develop a treatment program for your dog.
The facts about canine hip dysplasia appear simple. Hip dysplasia is a polygenetic disease, one that is caused by several genes, with an environmental influence. Thus some dogs that are predisposed to the disease by their genes will not develop it if the environmental factors are missing from their lives.
The hip joint is a ball and socket arrangement in which the femoral head (the ball) of the thigh bone (the femur) fits into the acetabulum (the socket) of the pelvic structure. The assembly is held in place by ligaments and muscles. Malformation of either the femoral head or the acetabulum, laxity in the ligaments, and poor muscle condition all contribute to the pain and ultimate arthritis of the disease.
But the disease is not as simple as this description implies. A dog can be dysplastic in one or both hips, can have a shallow socket and a normal ball, a malformed ball and normal socket, a shallow socket and malformed ball, a misaligned joint, loose ligaments, or a combination of these structural problems complicated by environmental factors such as rate of growth, level of nutrition, and exercise. Fast-growing puppies of large breeds are more at risk, even if both parents had excellent hips, because their bones, muscles, tendons, and ligaments may grow at different rates. Other factors include abnormal forces during weight-bearing that can stretch and tear the joint capsule, fracture the acetabular rim, or otherwise deform the joint.

Treatment
Surgery is a viable option for dogs with severe dysplasia. In these severe cases, veterinary surgeons can replace the hip with an artificial joint. However, most dogs require relief from pain and a moderate diet and exercise program to reduce the effects of the disease. John Cargill and Susan Thorpe-Vargas wrote a multiple-part series on hip dysplasia in Dog World in 1995 that covered the disease from diagnosis to surgical intervention. Although geared to breeders, the series had some useful information for the pet owner who discovers that his dog has hip problems. MedVet Review, a newsletter published by MedVet in Columbus, Ohio, also has some tips for management of the dysplastic dog.
Many dysplastic dogs are overweight, so a reducing diet is in order if the dog’s weight is causing undue pressure on his hips. Enforced rest is the simplest therapy for short-term relief, according to MedVet, and swimming is the best exercise because it can strengthen the muscles around the hips without causing pain from weight-bearing. MedVet recommends 15-20 minutes of swimming two-to-five times per week for relief.
Like humans with an injury, dogs with hip dysplasia may compensate for the loss of rear end motion and the pain involved in weight-bearing exercise by shifting balance, a disturbance that can cause spinal problems. Range-of-motion stretching exercises can help prevent muscle atrophy and keep the joints flexible. Chiropractic treatment may help relieve the stress of the disease on the spine. Owners of dysplastic dogs can learn to do stretching exercises from their veterinarian or a chiropractor.
Drug therapies are helpful to deal with pain. Non-steroidal anti-inflammatory drugs such as aspirin, naproxen, adequan, and cosequin have been proven effective in many cases. A dose of aspirin or other drug is often helpful before a bout of exercise. However, since aspirin is not tolerated by some dogs and can cause internal bleeding, and determining proper doses of naproxen can be difficult, doses should be prescribed by a veterinarian who has examined the dog, not by the dog owner. Some dogs respond well to phenylbutazone, but this drug can suppress bone marrow formation.
Corticosteroids should not be used to treat arthritis because they have adverse effects on cartilage and other unacceptable side effects.
Although no scientific studies have been done on the effects of acupuncture on hip dysplasia, anecdotal evidence attests to the potential for its successful use to relieve pain and promote natural healing, according to Cargill and Thorpe-Vargas in the October 1995 Dog World.
There are cases in which surgery is necessary. If the dog does not respond to the chosen therapies and continues to be in pain, a veterinarian may recommend one of the following surgeries:
• Triple pelvic osteotomy, a procedure to stabilize the joint and prevent degenerative changes that accompany weight-bearing stress on an abnormal hip;
• Femoral head excision to prevent bone-on-bone friction; or
• Total hip replacement.
The decision on type of surgery is based on the age of the dog, the progress of the disease, and the general health of the animal.
Sally and Dr. Jones decided to use a combination of therapies for Ranger. She could take him swimming a couple of times a week, learn to do the range-of-motion exercises, try a course of adequan treatment, keep him from climbing stairs and jumping (no more agility class or open obedience), and have him examined by a chiropractor. Dr. Jones would examine him again in six months and prescribe changes in the protocol if necessary.
Like most dogs with mild hip dysplasia, Ranger has good days and bad days. Sally has learned to accept his limitations and to relax about the diagnosis – while often painful and sometimes debilitating, mild-to-moderate hip dysplasia in the young dog can be successfully treated without resorting to surgery.
Norma Bennett Woolf