HIP DYSPLASIA IN DOGS



By breeding only those dogs certified as free of dysplasia, we continue our efforts to eliminate the disease. The system is working. It has been shown that in those breeds actively using OFA certification, the incidence of the disease is decreasing. If you are not x-raying your breeding animals, then you may contribute to the problem rather than the solution. Selective breeding is crucial!

"Canine hip dysplasia is one of the most baffling diseases afflicting dogs today," said George Lust, Ph.D., the Cornell professor of physiological chemistry. "We know this is an inherited disease, but identifying the so-called 'hip dysplasia gene' is proving difficult because this seems to be a polygenic disorder, with several different genes responsible. Furthermore, these may be 'masked' or hidden genes that are not expressed in several generations until the disease turns up again in the progeny. That's why there is such a low level of confidence when breeders say: 'There is no background of hip dysplasia in my dogs' lines.' "

Hip dysplasia is a very common problem causing pain and lameness in large breed dogs. The word dysplasia is a little bit intimidating and non-medical people seem to assume that the disease is very complicated. Actually, the problem is quite simple.

It's the solution that's everybody's confused about, the medical profession included.

Here are the basics:

An Introduction to Hip Dysplasia

  1. 1. In simple terms, all hip dysplasia means is that the head of the femur bone (thigh bone) doesn't fit into the hip socket properly. This causes abnormal wear and tear of the cartilage in this high stress joint, and this, of course, leads to gradual destruction of the joint as well as pain and inflammation. This disease is often crippling.

  2. There's overwhelming evidence that the poorly formed hip joint that causes hip dysplasia is a genetic problem. That's why breeders and the veterinary profession make such a big deal about trying to identify dogs with hip dysplasia early enough to prevent them from breeding. It's why breeders go to great expense and effort to prove that the parents and grandparents of the pups they sell are hip dysplasia free.

  3. But it's very difficult to detect all but severe hip dysplasia in the early years of a dog. The joint usually looks normal on radiographs and there's usually not any obvious signs of lameness until middle age. Just to avoid confusion here, some dogs have obvious hip problems as early as 5-6 months of age (extreme cases) and other pets get around well until late in life (mild cases). Other pets don't exhibit any lameness or pain but can still be genetic carriers of the disease. But for most pets, clinical signs start becoming apparent to the observant owner in early middle age. Often your vet will pick up the early signs during routine exams. (Yet another example of the importance of regular check ups if you really care about your pet)

  4. Early signs of hip dysplasia in a dog include hopping like a rabbit with the rear legs when running, difficulty in rising from a sitting position, stiffness in the first few steps after lying down, and a reluctance to walk normal distances or play as hard or as long as normal dogs of the same age.

    These signs are often more evident after exercise.

  5. As the problem becomes more severe, they become more obviously lame and are often reluctant to go on walks or to play like they used to. It hurts.

 

What To Expect When You Go To The Vet For Hip Dysplasia

(Of course, your vet may do things a little differently)

If we're talking about hip dysplasia (and we are), you'll be going to the vet for 1 of 3 reasons:

  1. Your dog is often lame, stiff, sore, reluctant to get up and down, has trouble getting up or down steps, "bunny hopping" and so forth. In other words, it's becoming obvious to you that something's wrong with the rear end of your dog.

  2. Your dog seems fine, but you're a concerned, aware, and super responsible pet owner or breeder who wants to know if your dog has hip dysplasia and you want to know this early enough to prevent breeding this pet and/or to manage this disease in the early stages to minimize future problems.

  3. You, the responsible and caring pet lover will be seeing your vet for some other problem or for your pet's annual exam and your astute and wonderful veterinarian will detect or suspect hip dysplasia and offer you advice and options

Our Diagnostic Options:

Unfortunately, as I indicated in the introduction, it's quite difficult to determine if a young dog is a genetic carrier of hip dysplasia or is likely to suffer from the disease in latter life. There aren't as yet, any blood tests, genetic tests, etc that detect the disease. Perhaps such tests will be available soon, which would be great, because then we could avoid breeding carriers of the disease and maybe in one or two decades hip dysplasia would be a rare disease instead of the the most common crippling disease we vets see after car accidents.

So, here's what we do have:

  1. Our skills and experience to recognize the disease with a good exam and history. Detecting hip dysplasia in this manner is usually too late for making breeding decisions...but it's often early enough to make some changes that will greatly minimize future suffering of the pet involved.

  2. Radiographs. This is our main tool. High Quality radiographs can detect the poorly shaped hip socket long before the pet exhibits lameness.

By two years of age, a pet's pelvic bones are fully developed and by convention, we recommend taking x-rays of large breed dogs at 2 years of age prior to breeding in hopes of breeding only those individuals without obvious problems. The success of this world-wide endeavor...trying to avoid breeding of hip dyplastic dogs...has been limited by various hurdles, non-compliance, and the inability of radiographs to detect non-symptomatic carriers of the disease. I'm going to skip over this topic and get back to what to expect at the vet for your individual pet except to say that we strongly encourage you to avoid having puppies with breeds prone to hip dysplasia until after having radiographs that rule out obvious hip dysplasia. You don't necessarily have to wait until the dogs are 2 years old for the x-rays to pick up bad cases of dysplasia, so if you're anxious to breed, talk to your vet about pre-breeding radiographs. (There is a 2 year old requirement for official certification and it's true that x-rays taken before physical maturity of the pelvis aren't as accurate)

If you take your pet to the vet for lameness etc and hip dysplasia is suspected, your vet will encourage you to take radiographs for a couple of reasons:

  1. To confirm the disease and to make sure there isn't some other explaination or problem that needs to be tackled. Quite a few times in my experience what I suspected was hip dysplasia turned out to be an old fracture, a pellet or bullet, disc disease, bone cancer, an adominal tumor, or a prostatic cyst. One time it turned out to be from a bone pin that was put in years ago when the young dog fractured it's femur; the pin had migrated up into the socket. You never know unless you look.

  2. To see how bad the condition is (staging), to see if one side is much worse than the other (making a femoral head removal a possible option), and so that we compare to future radiographs which allows us to determine if our treatment plan is working well or not.

Treatment
I'll tell you up front, we don't have a cure or super great treatment for hip dysplasia yet. Whenever this is the case...where we can't all agree on which treatment is best...you'll find some vets enthusiastic about one type of treatment and others all for another type or method of treatment. And often it depends on what you can afford or are willing to spend. Here the more common options:

Medical Treatment and Relief of Symptoms for Hip Dysplasia

  1. Weight Loss I mention this first for no special reason, but if your dysplastic pet is overweight, it's well worth the trouble and effort to get that weight off.

  2. Pain and Inflammation Relief. New medications available (Rimadyl, Ectogesic, and Deramaxx) have been wonderful, giving a lot of suffering pets the relief needed to live a fairly normal life. Prior to the availability of these new meds, we used aspirin, bute, motrin, and steroids with varying degrees of success, but these newer medications are much better and safer.

  3. Joint Lubrication and medications that promote joint health: This group of medications includes glucosamine, vitamin C, injections into the joint, anti-oxidants, MSM, and probably other supplements and medications I'm not familiar with yet. Such treatments are still somewhat controversial.

There's little doubt left that these treatments are often beneficial; they are. The remaining controversy centers on how beneficial, which brands are the best, which combinations are the best and so forth. I personally am a big fan of the Glucosamine-MSM-VitaminC product made by VetriScience.

At any rate, such products help to increase joint lubrication, reduce damage to the cartilage, and to some degree help repair cartilage damage. To put a finer point on the topic; if your pet is stiff, sore, or limping due to dysplasia, you have about a 30% chance of noticing great improvement after using high quality glucosamine combinations (it takes 1- 3 weeks to see the improvement). You have about a 30% chance of seeing some improvement, and about a 30% chance that no obvious improvement will be noted.

Even then, it might be worth giving for the academic reason that we know such products at least slow down the destructive joint chances that occur with dysplasia.

  1. Acupuncture. I just don't know enough about the pros and cons of this treatment modality to advise you. It's got a lot of popular press and mystique, but that doesn't necessarily make it a good choice.

  2. Chiropractic. I'm impressed with the benefits of chiropractic treatment for some spinal injuries...and arthritis of the lower spine is often present in dogs suffering from hip dysplasia, in which case I think chiropractic treatment might be very helpful. But: I don't see how spinal adjustments are likely to help the wear and tear pain associated with a bad hip joint.

Surgical Treatment Options for Hip Dysplasia
Medical treatment and acupuncture can be used to alleviate arthritis pain and promote joint health, but these treatments do not correct the underlying cause of the hip pain which is a malformed joint. Because of this, the primary treatment for hip dysplasia is surgery and it can be very successful.

Removal of the Femor Head and Neck so it doesn't rub against the pelvis

This is the surgery I do most often, mainly because it's relatively inexpensive, usually works fairly well, and just so you know; it's the only procedure for hip dysplasia I know how to do well. We simply remove the top of the femor and that solves the painful problem of grinding away at the hip joint. Of course, without the leg bone attaching to the hip bone, you might think that the poor animal would be unable to stand on that leg...and it's true...at first, but after a few weeks a false joint is formed by the muscle being scarred around the top of the cut off femor and most patients are soon weight bearing and get along quite well. This is not a perfect solution by any means, but it does allow most pets to get around without a lot of pain. This is an especially good choice if only one leg is bad or you simply can't afford other methods of repair. Some vets do both legs at the same time, others, like me, usually do one leg at a time.

Total Hip Replacement

Total hip replacement is used primarily for larger dogs and is very similar to the procedure performed on people.

The entire hip is replaced using high density, medical grade plastic for the socket and a high quality, non-corrosive alloy for the ball.

This is probably the very best solution for many patients and has a high degree of success, pain elimination, and nearly complete resumption of activity. This type of surgery is done by specialists and is quite expensive.

Triple Pelvic Osteotomy

This special surgery is different in that it must be done BEFORE the joint is damaged and is done on dogs under a year old in order to prevent future dysplastic problems.

We perform this surgery on young dogs with early symptoms or radiographs indicating malformed joints. Some owners with breeds prone to hip dysplasis...or with puppies from a line of hip dysplastic dogs...will sometimes have x-rays done as early as 6 months old that can detect an obviously malformed hip joint. In these cases, this surgery works well at preventing future pain and problems.

The surgery basically involves cutting the pelvis in 3 places which allows the surgeon to rotate the hip sockets to better fit over the femor heads. The pelvis then heals into this new and better position. This is another surgery done by specialists and is quite expensive.

Other Surgical Methods

There are quite a few other methods that have been tried and are in the "surgical literature" but as far as I know, none of them were successful or practical enough to become popular


Article submitted by: © Roger Ross DVM
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FIVE MISCONCEPTIONS ABOUT CANINE HIP DYSPLASIA

  • Only hip joints and surrounding tissues are affected.
    Rather, evidence now indicates that the shoulder and knee joints and some intervertebral joints may show similar changes: the loss of cartilage, inflammation of the joint capsule, bone damage and the growth of spurs at the bone-cartilage interface. Hip dysplasia is simply the most conspicuous and most painful manifestation of this form of osteoarthritis. 

  • Only dogs suffer hip dysplasia.
    While 50 percent of some of the larger dog breeds are afflicted, the disease is not unknown in humans. About 1 percent of the general human population suffers hip dysplasia, and the rate for the inherited disease is higher in some populations of American Indians. Many Navajos in New Mexico went through life with hip dysplasia until mothers stopped the traditional practice of strapping infants, straight-legged, to cradle boards and allowed babies to assume the more relaxed, bent-legged position. Replacement of diseased hip joints with artificial joints is one treatment, both for canine and human patients.
  • Absence of hip dysplasia in canine parents guarantees dysplasia-free pups.
    Unfortunately, out of 100 matings of "normal" dogs in breeds affected by hip dysplasia, 75 percent of puppies will be "normal" but 25 percent, on average, will have hip dysplasia. Genes for hip dysplasia are believed to be "masked" or hidden in some generations, making the elimination of the disease from breeding stock even more difficult. Canine hip dysplasia was first diagnosed in the 1930s, but probably has troubled domestic and wild canines for centuries.
  • All large-sized breeds of purebred dogs are candidates for hip dysplasia.
    Although the disease is particularly common among certain large breeds (from Bernese Mountain Dogs, Bloodhounds and Boxers to Rottweilers, St. Bernards and Welsh Corgis) mixed breeds of all sizes also are subject to hip dysplasia and not even the toy breeds are spared. However, the incidence is lower in small dogs. Large-sized breeds with a relatively low incidence of hip dysplasia include the Borzoi, Doberman Pinscher, Great Dane, Greyhound, Irish Wolfhound and Siberian Husky.
  • A hearty diet helps avert hip dysplasia.
    To the contrary, dogs that are genetically predisposed to hip dysplasia seem to benefit from a lean diet during their first two years. In one study beginning at eight weeks of age, pups that were restricted to a 24-percent smaller ration had a 46-percent lower occurrence of hip dysplasia than pups that could eat freely. Slowing the growth rate during the early months of life, some veterinary nutritionists now believe, can lessen the severity of hip dysplasia and even prevent it.

From the John M. Olin Laboratory for the Study of Canine Bone and Joint Diseases
James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University

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