Dysplasia: Coming to grips with bad hips.

Friday, December 16, 2011

by Steve Marsden, DVM, ND, MSOM, LAc, Dipl. CH

If you have a large dog, you're probably concerned about canine hip dysplasia (CHD), a common disorder that strikes many bigger breeds. When I was a boy, we had a great Dane named Gerda with a host of problems, one of which was hip dysplasia.

THE DAILY GRIND

Dysplasia means "abnormal growth," in this case of the "ball-and-socket" hip joint. The head of the femur fits into the acetabulum of the hip the same way a softball fits into a baseball glove. Imagine trying to catch a basketball with a baseball glove, and you have a basic idea of hip dysplasia. The acetabulum in affected dogs is too small and flat to get itself around the head of the femur, which consequently wiggles and slides around.

The more it wiggles, the more the femur wears down the cartilage lining the joint and tugs painfully on the capsule surrounding it. All that grinding eventually leads to permanent bony deformities known as degenerative joint disease, a leading cause of death in dogs. As the joints become increasingly painful and damaged, the dog becomes unable to get up and has to be euthanized. This is what happened to Gerda.

Obesity and too much exercise aggravate the wear and tear of degenerative joint disease. A lack of exercise can also cause the disease because it leads to atrophy of the hind limbs, weakening the muscles so they can't stabilize the hip. If your dog has CHD, the best advice is to find the maximum level of exercise he can tolerate without pain, and provide it several times a week. A diet low in fat and carbohydrates, meanwhile, can help with weight control.

The typical treatment for CHD is surgery for dogs that can withstand it, and painkillers for those that can't. In Gerda's day, the surgical options and non-steroidal anti-inflammatory drugs currently available were non-existent. Hip dysplasia seemed a problem without a solution - and still does if the disease is too advanced, or if you can't afford the high cost of the treatment.

We could do very little but watch Gerda slowly decline until she had to be put to sleep. Not a week goes by that I don't wish I knew then what I know now about hip dysplasia treatments such as acupuncture, chiropractic, homeopathy, herbal medicine and nutrition.

X-RAY RATED

Hip dysplasia is a fact of life for large breeds such as Labrador Retrievers, Rottweilers, Great Danes, German Shepherds, Rough-Coated Collies, and even not-so-big Cocker Spaniels. These breeds are genetically predisposed to CHD. Nor do they have to be purebred to get hip dysplasia.

We have been selectively breeding dogs for decades to get rid of CHD. So why hasn't it happened yet? It's because several genes are responsible for the disease, and can be carried by both parents. In addition, if the genes always showed themselves by producing terrible hips, we would be able to pick out affected dogs and avoid breeding them. However, you can't tell from outward appearances whether or not a dog has poor hips, even if he's carrying a few CHD genes. If he breeds with another dog who also carries a few of the troublesome genes, a puppy with hip dysplasia may result, leaving us right back where we started.

To identify as many partially affected dogs as possible, veterinarians use radiographs or X-rays taken at two years of age or older.

IS SURGERY THE CUTTING EDGE OF TREATMENT?

Abnormal hip joint structure appears to be the problem in CHD, so many veterinarians consider surgery the only real solution. Various techniques are used, such as prosthetic implants similar to those used in humans. Others include Triple Pelvic Osteotomy (TPO) and fusing the pubic symphysis of young predisposed dogs.

To get an idea of how these techniques work, think about holding an inflatable ball underwater. The only way you can do this is if your hand is positioned perfectly over top of the ball. Likewise, the goals of TPO and fusing the pubic symphysis are to rotate the acetabulum over top of the femoral head as much as possible, so the femur will push up into it.

Generally, TPO and prosthetic hips are very satisfactory, with over 80 percent of dogs showing a significant improvement in mobility. Good results with TPO are more likely in younger dogs, where good coverage of the femoral head is more likely to be achieved. These surgeries are extremely expensive, however, with each hip costing several thousand dollars. They're also extensive, and can only be considered for young dogs in good health.

THE LIGAMENT CONNECTION

Another reason to look beyond surgery is that bony conformation is not the only problem in hip dysplasia. A study of dogs that received TPO revealed that while 80 percent experienced gait improvement, the hip joints in over 40 percent continued to degenerate because of laxity in the tissues holding the two bones together.

The main tissue anchoring the femur to the hip is a thick ligament most commonly called the round ligament. The health of this ligament plays a key role in the development of CHD. In fact, the earliest sign of the disease is not wear and tear of cartilage, but swelling and inflammation of the round ligament. Eventually, the ligament stretches, frays and finally ruptures as CHD progresses. Not surprisingly, then, the severity of joint damage in CHD is strongly correlated to the integrity of the round ligament. The most likely way alternative veterinary practitioners ease the pain of CHD and halt further joint degeneration is not by changing the structure of the pelvis, but by improving the health and integrity of the round ligament.

GET HIP TO ACUPUNCTURE

One effective alternative medical treatment for hip dysplasia is acupuncture, the insertion of fine sterile needles into the skin and subcutaneous tissues at special points. The exact function of each point varies with its location, but most are "hardwired" to the brain and spinal cord, and are believed to exert their influence through the central nervous system.

Most acupuncture treatments are repeated on perhaps a weekly basis until the patient is much improved. A more enduring form of single acupuncture treatment is to use a hypodermic needle to implant tiny gold beads at the acupuncture points. A study at Finland's University of Helsinki in 2001 showed a significant improvement in pain and gait abnormalities in 19 CHD dogs treated with gold bead implants.

Interestingly, there was no significant difference in pain relief between these dogs and 19 others who were needled around the hip at sites not known to be acupuncture points. Many veterinarians think of acupuncture as a short-term method of relieving pain, but the fact that this second group of CHD dogs improved so much in the six months following a single treatment suggests a more fundamental improvement must be occurring.

When ligaments are damaged, blood flow must be significantly increased for them to heal. A recent study in Calgary, Alberta revealed that ample blood supply to a damaged ligament is heavily dependent upon neural input. It's possible that acupuncture may increase neural input to the hip joint and the damaged round ligament, promoting healing and stabilization. While this is conjecture, it is certainly true that one of the main effects of acupuncture point stimulus is to increase blood flow to the area of the point. Once an adequate blood supply has been established, ligament repair will probably require at least six weeks.

Chiropractic seems to act synergistically with acupuncture by releasing nerve root impingement caused by an inflexible back. Once the vertebrae are released, pressure on the nerve roots is eased, allowing nerves to function better. Increased neural activity may lead to enhanced blood flow to the hip joint and increased tone in the muscles stabilizing the joint. Chiropractic also relieves any back pain that may be compounding the pain and weakness arising from CHD.

LIGHTEN UP

One of the earliest discoveries about canine hip dysplasia was that it is aggravated by excessive caloric intake. In one study by Purina, 48 eight-week-old Labrador retrievers were divided into two groups. One group was fed as much as they wanted while the other was given 25 percent less. Almost 70 percent of the dogs on the ad lib diet became dysplastic, compared to half that number on the restricted diet. Other articles advised limiting the food intake of susceptible dogs so their ribs and spine are palpable, but not visible. An article by Hill's Pet Nutrition in a 1992 edition of Veterinary Clinics of North America confidently asserts that "dietary deficiencies are of minimal concern in this age of commercial foods specifically prepared for young, growing dogs" and that dogs with CHD are more likely to have been over-nourished.

It's ironic that so many of these articles were contributed by commercial pet food companies, since their foods appear to be a big part of the problem. A 1992 review article noted that excess energy consumption increases the frequency and severity of hip dysplasia in genetically predisposed dogs. A 1993 article observed that foods high in carbohydrates promote degenerative joint disease, and cited low protein diets as a direct cause of hip dysplasia. Human medical research has shown that excessive carbohydrates lead to the production of free radicals that can inflame and damage the joints.

Unfortunately, diets low in protein and high in carbohydrates are the main strategy for geriatric dogs, in which lameness is often a major concern. So-called "high protein foods" also contain as much as 30 to 40 percent carbohydrates. Overall, the research suggests that high protein and low carbohydrate diets may be best for preventing hip dysplasia, while diets containing excessive calcium and vitamin D should be avoided.

In 1992, a study at Cornell University studied the effects of injectable glucosamine on CHD. The hip development and laxity of puppies given 2.5 to 5 mg/kg of injectable glucosamine until eight months of age was compared to that of puppies from the same litter who received a saline placebo. All puppies receiving glucosamine demonstrated improved hip conformation and no subluxation over dogs receiving the placebo.

Most veterinarians administer glucosamine orally, not by injection. They also tend not to use it preventively, but to administer it to dogs that already have problems.

Despite its widespread use, the benefits of oral glucosamine supplementation in CHD are not known and have never been researched. It may be of some benefit, however, given the results of studies using injectable preparations. In 1994, a study at the University of Florida showed that glucosamine injections at a dose of 4.4 mg/kg produced noticeable improvements in dogs with CHD. Dogs receiving placebo benefited the least. Overall, however, there was no statistically significant benefit between treated and untreated dogs, suggesting that any benefit of oral glucosamine supplementation in CHD is more likely to be seen when administered to young developing dogs. Therapeutic benefits of oral glucosamine may be hampered by impaired absorption, inconsistent use, improper dosing, and variations in quality among supplement manufacturers.

Another popular treatment for hip dysplasia is supplemental vitamin C (ascorbic acid). Unlike humans, dogs can make their own vitamin C, but administering extra may promote collagen synthesis, which is required for ligament repair. In addition, vitamin C is an antioxidant and can neutralize free radicals that might damage joints.

Conventional researchers insist there is no evidence vitamin C aids hip dysplasia. In a 1990 study, however, 71 percent of a group of dysplastic dogs given 30 mg of polyascorbate three times daily for six months improved within one week. The remaining 28 percent received a smaller benefit. Such a rapid response to vitamin C suggests its main benefit in CHD may be to quench free radicals associated with joint and ligament inflammation.

Many herbal formulas exist for hip dysplasia. They are often anti-inflammatory but may also increase blood flow through the hip joint. Some also promote relaxation in the lower back, resulting in reduced nerve root impingement, increased muscular strength, and improved blood flow to the hip joint. For optimum results, individualized prescriptions are necessary.

Substantial pain relief may be achieved through some commonly available homeopathic remedies, but like herbs, they must be individually prescribed for the best results. One useful remedy is Rhus toxicodendron. It can be used for lameness aggravated by cold, damp weather, and/or lameness that is worse with initial movement, better with sustained movement, but aggravated by overexertion. A 30C potency can be used once to twice daily as needed, for up to three weeks at a time.

So don't despair if you have a dysplastic dog, or one prone to developing the disease - expensive surgery and drugs are not the only answers. A holistic vet will have a range of gentler solutions that will help keep your dog mobile and free of pain.

VETERINARIAN STEVE MARSDEN LECTURES AROUND THE WORLD ON ALTERNATIVE VETERINARY MEDICINE. HE HOLDS A MASTER'S DEGREE IN ORIENTAL MEDICINE FROM THE NATIONAL COLLEGE OF NATUROPATHIC MEDICINE IN PORTLAND, OREGON, AND IS CERTIFIED IN ACUPUNCTURE AND CHINESE HERBAL MEDICINE. BASED IN EDMONTON, ALBERTA, HE IS CO-FOUNDER OF THE EDMONTON HOLISTIC VETERINARY CLINIC AND CO-AUTHOR OF THE Manual of Natural Veterinary Medicine: Science and Tradition WITH SUSAN WYNN.

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