Canine Hip Dysplasia

Hip dysplasia, or HD, is a medical term that covers a number of abnormal conditions of the acetabulum and the head of the femur. In other words it describes a malformation of the femur head and/or the socket of the hip where the femur head rests, that leads to debilitating arthritis of the hip joint.  As a result of this malformation, the bones are in contact with each other causing them to rub together, which eventually leads to arthritis.

Some of these conditions are hereditary, they include:

 Sublaxation in which the head of the femur is no longer firmly seated within the acetabulum.  Deformity of the head of the femur gradually develops

Osteochondritis dissecans where muscle wasted and lameness occur usually in one limb

Congenital Dislocation in which the acetabula are too shallow to retain the heads of the femur in position.

Slipped Epiphysis This also causes pain and lameness at 4-6 months and is difficult to distinguish from osteochondritis dissecans

Depending on the severity of dysplasia, outward signs can range from nothing at all, to severe pain. The only way to conclusively diagnose HD is through X-rays. The condition results from an inherited tendency for rapid bone growth without concurrent muscular growth to support the skeletal structure. The rapid bone growth results in laxity of the hip joint and deformation of the cup and ball portion of the joint. The laxity concentrates the weight bearing stress to a relatively small area of the cartilage. This leads to cartilage damage and development of arthritis.

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The hip joint is a "ball and socket" joint: the "ball" (the top part of the thigh bone or femur) fits into a "socket" formed by the pelvis. If there is a loose fit between these bones, and the ligaments which help to hold them together are loose, the ball may slide part way out of the socket (subluxate). With time, as this occurs repeatedly, other degenerative changes in the joint occur (also called osteoarthritis) and your dog will become painful, lame and weak in the hind end.

This disease is progressive; that is, it gets worse with time.

How is hip dysplasia inherited?
The mode of inheritance of this disease is polygenic (caused by many different genes). Scientists do not yet know which genes are involved, or how many genes. Factors that can make the disease worse include excess weight, a fast growth rate, and high-calorie or supplemented diets.

What breeds are affected by hip dysplasia?
Hip dysplasia is the most common inherited orthopedic disease in large and giant breed dogs, and occurs in many medium-sized breeds as well. When obtaining a dog from a large or giant breed, you should ask the breeder about hip certification in their breeding dogs, and for several generations back.

For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have only listed breeds for which there is a strong consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.

What does hip dysplasia mean to your dog & you?
While there is a severe form of hip dysplasia that affects young dogs (less than one year of age), signs of this disease are most common in older dogs. The loose fit at the hip joint will be present in young dogs, but it may take years for the other changes (such as osteoarthritis) to cause pain. Your dog may be painful after exercise, have difficulty with stairs, or even have difficulty getting up. You may only notice this once in a while, but over time you will find it getting worse. There is no cure, but your dog’s pain and lameness may be reduced by making sure that s/he is not overweight, restricting exercise, and using pain-relieving medications and/or alternative therapies such as acupuncture.

Large and giant-breed dogs are more likely to get hip dysplasia later in life if they are overfed and gain weight quickly as puppies. If you have such a puppy, you may be able to reduce the chance of future hip dysplasia by careful feeding. Your veterinarian can help you determine the right body weight and diet for your dog.

How is hip dysplasia diagnosed?
Your veterinarian will probably suspect hip dysplasia if your large or giant breed dog has pain or lameness in the hips. Your vet will take x-rays to evaluate the general fit of the femur and pelvis, and to look for any osteoarthritic changes in the hip joint. Usually sedation or anaesthesia is required to ensure proper positioning of the dog.  In order to see how much looseness there is in the hip joint, your veterinarian may take special stress or distraction radiographs.

For the veterinarian:  There are several established scoring systems to evaluate radiographs for the presence of hip dysplasia. The Orthopedic Foundation for Animals evaluates a standard ventrodorsal view with hips extended and stifles rotated internally. Radiographs are scored based on degenerative joint changes and evidence of subluxation. Dogs must be 2 years of age in order to be certified by the OFA.

The PennHip method uses a quantitative measure of joint laxity (based on distraction and compression views) to determine the Distraction Index (DI), as well as the standard hip-extended view, to evaluate a dog for hip dysplasia (see Smith and McKelvie,1995, below). Dogs may be evaluated by this technique as young as 16 weeks of age.

How is hip dysplasia treated?
The degree to which the hips are dysplastic does not always correlate with the amount of pain. Some dogs with very bad hips radiographically are less painful than others whose x-rays show only minor changes.

Although there is no cure for hip dysplasia, there are ways to manage the pain. Your veterinarian will  work with you to keep your dog comfortable. Treatments include anti-inflammatory drugs and/ or alternative therapies such as acupuncture. Nutraceuticals such as glucosamine may also be helpful. Controlling exercise and maintaining your dog at an appropriate weight, are important in managing the pain.

Your veterinarian may suggest surgery (such as hip replacement) if the pain is severe, and/or can not be controlled by medical treatment as above.

Breeding advice
Canine hip dysplasia remains a problem in most large and giant breeds of dog, despite efforts to control this condition dating back to the 1960s. Because it is virtually impossible to determine the exact genotype, it is difficult to control defects like hip dysplasia that have a polygenic mode of inheritance. The best attempts at control are based on a grading scheme for identification of the defect and a breed policy of recording and publishing the results for as many dogs as possible.

Breed organizations and veterinarians in various countries have developed control programmes that rely on radiographic evaluation and a central registry of dogs. Dogs from large and giant breeds should be evaluated by one of these established screening programmes before breeding, and should be bred based on the guidelines of that programme. The distraction index (DI) is determined by the PennHip technique and is statistically the most predictive method for hip joints in pups. Essentially, the best way for breeders to prevent hip dysplasia is to breed only dogs that have disease-free joints, based on appropriate radiographic evaluation, and that come from families with disease-free joints. Do not breed dogs whose offspring have hip dysplasia (dogs with hip dysplasia can produce normal offspring, and normal-appearing dogs can produce offspring with hip dysplasia).

Two registries that keep statistics on hip dysplasia are the Institute for Genetic Disease Control (GDC - www.vetmed.ucdavis.edu/gdc/gdc.html) and the Orthopedic Foundation for Animals (OFA - www.offa.org) Thoughtful selection by breeders, using dogs from these registries, has reduced the incidence of hip dysplasia in some breeds and some areas.

Resources
Leighton EA. 1997. Genetics of canine hip dysplasia. JAVMA 210(10):1474-1479.
Martinez SA. 1997. Congenital conditions that lead to osteoarthritis in the dog. Veterinary Clinics of North America Small Animal Practice. 27(4):735-758.
Richardson DC. 1995. Developmental orthopedics: Nutritional influences in the dog. In EJ Ettinger and EC Feldman (eds) Textbook of Veterinary Internal Medicine, p. 252-258. WB Saunders Co., Toronto.
Smith GK, McKelvie PJ. 1995. Current concepts in the diagnosis of canine hip dysplasia. In JD Bonagura (ed) Kirk's Current Veterinary Therapy XII Small Animal Practice p. 1180-1188. WB Saunders Co., Toronto. Describes PennHip technique.
Smith GK. 1998. Advances in diagnosis of canine hip dysplasia. ACVIM-Proceedings of the 16th Annual Veterinary Medical Forum. p. 569-571.
Swenson L, Audell L, Hedhammar A. 1997. Prevalence and inheritance of and selection for hip dysplasia in seven breeds of dogs in Sweden and benefit cost analysis of sceening and control program. JAVMA 210(2):207-214.
Copyright © 1998 Canine Inherited Disorders Database. All rights reserved.  Revised: November 28, 2002.
This database is funded jointly by the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association.

reprinted with kind permission from:-
 Alice Crook, DVM,Coordinator, Sir James Dunn Animal Welfare Centre, Atlantic Veterinary College,University of Prince Edward Island, 550 University Ave.Charlottetown, PEI C1A 4P3
http://www.upei.ca/cidd 

A Diet for Bad Hips

    

Radiograph  ("x-ray") of a ten month old Beagle/Rottweiler mix	The same dog's radiograph ("x-ray") at 4 years of age

HIP DYSPLASIA in dogs!  With this report we'll clear up some misconceptions, describe what CHD is, what effect the condition can have on the dog and what  can be done about it.   Because Hip Dysplasia in dogs is a complex topic, it requires extensive consideration in order to have a good understanding of its nature.  Cats do suffer from Hip Dysplasia, too, but it is seen less frequently in cats.


WHAT IS IT: "Hip dysplasia" simply stated means an "abnormal formation" of the hip joint. Think of the condition first as a looseness in a joint that should be snug - then most of the problems attendant to hip dysplasia are a result of this "looseness".   See the image on the right a few paragraphs down for an example of a nice, normal, snug hip joint.

The normal anatomy of the hip joint is a classic Ball and Socket joint.  The head of the femur (the "Ball") is supposed to match the acetabulum (the "Socket").  A good hip joint has a neat, snug fit between the ball and socket - that is, the head of the femur should not be slipping and slopping around somewhere in the neighborhood of the acetabulum!

There are infinite variations of dysplasia - ranging from only very slight changes from normal to complete dislocation.  (There are a number of examples of actual radiographs in the table near the bottom of this page.  Click on any x-ray image to enlarge it.)  Consequently, no two dogs will be affected by CHD exactly alike.

HOW IS CHD ACQUIRED?  This is one disorder that has been proven, positively, to have a genetic basis.  How much of a genetic origin in each case can vary from 25% to 85%.   A condition that is completely determined by genetics, for example gender, has a Heritibility Factor of 1.  A condition totally unaffected by genetics, for example a broken leg, has a Heritibility Factor of zero.


Studies have shown that CHD's Heritibility factor ranges from .25 to .85; this is a significant genetic contribution.  So the Heritibility Factor for a given dog is the result of a combination of the Heritibility Factors from each parent.  Simply put . . . if the parents are carrying genetic material for hip dysplasia - so will the offspring.   And the greater the genetic contribution for loose hips or malformed bone or abnormal muscle mass (Heritibility Factor) from the parents, the greater the chances for hip dysplasia in the offspring.

 

The expression of hip dysplasia in any dog has other determinants, though; genetics play only a varying role in the total picture.  The effect of the developing dog's environment does play a role in the clinical (observable) signs of dysplasia, although just like the genetic component the effects of environment are variable and not completely understood.  To illustrate the complexity of the environmental issue, listen to this: It is possible for a dog with known genetic components for hip dysplasia (called genotype) to not show any clinical signs of trouble if the environmental factors are favorable. So the dog can be dysplastic and not show observable signs of it until middle or old age.  I have seen this fairly commonly in practice and it is always an important issue with breeders who assume that their dog is normal just because it hasn't shown any signs of hip trouble.  Why take pelvic x-rays for dysplasia when the dog has always acted perfectly fit, they reason.  There is no excuse for NOT taking pre-breeding x-rays.  I have seen a number of breeders who sold litters of pups where the parents have not been x-rayed for CHD and who were shocked a year or so later when the phone started ringing about "that pup you sold has hip dysplasia".  Trust me, it happens.  Also, if two dogs that have the same genotype (genetic makeup) are exposed to different environmental conditions, their expression of hip trouble can be quite dissimilar.  Little wonder that the topic has such a wide range of information and misinformation regarding it.

Some of the environmental aspects that can affect the observable expression of hip dysplasia are the following:

1. Nutrition - There are reports that in puppies a restricted calorie intake could restricted the growth rate, and in turn will lessen the potential for the dog to develop hip dysplasia.  (I wouldn't suggest doing this to any pup... it makes as much sense as stealing money from your own checking account!)  The problem is that some restricted diets restrict the fat and protein content and increase the carbohydrate content of the food.  Bad!  See a better way in the discussion in ThePetCenter.com here.  The real goal should be to keep growing pups from becoming OVERWEIGHT.  Restricting fat and protein in a growing pup can be a disaster.  A high quality, meat-based diet is absolutely necessary for growing pups, just don't feed so much of it that the pup becomes overweight.

2. Physical Activity - In a young, growing dog with a genotype (genetic makeup) for CHD who will eventually develop some trouble because of it, will develop more arthritis and have more eventual difficulty if it is highly active physically.  Climbing stairs, jumping into and out of pick-up trucks, running with other normal dogs can all subject the growing hip structures to unwarranted stress and trauma and increase future discomfort for the dog.  The effects of this excessive activity is worsened in an overweight pup. (In a normal, growing dog, all these activities will not cause hip dysplasia!)

3. Bedding - There is no scientific proof,  but lots of observational conclusions, that pups reared especially during the nursing period on slippery surfaces such as newspapers will be prone to hip difficulties.  That is not to say that smooth concrete, wood or newspaper surfaces cause dysplasia, just that they can make a bad situation worse.   Better surfaces for newborn pups would be blankets or towels... something they can get a better grip on.

MUSCLE AND CHD:  Research has shown that dogs with CHD have significantly decreased sizes of total pelvic musculature surrounding and acting on the hip joint.  Whether this is a contributing factor or a result of hip dysplasia remains to be proven.
One muscle that can contribute to worsening of hip dysplasia is the Pectineus Muscle.   In dogs with a strong genetic background for CHD, the microscopic makeup and contractibility of the Pectineus Muscle are strikingly different from the same muscle of normal dogs.  The theory is that a tight or inelastic Pectineus Muscle causes tension in such a direction that the force tends to pull the head of the femur away from the acetabulum.  So the tight muscle creates more looseness in the joint.  I have had good results in about 50% of the cases I have surgically excised a portion of the Pectineus Muscle.  The patients were more comfortable and mobile almost immediately.  This Pectineal Myotomy surgery has no effect on the arthritic changes in the hip joints; it can make the dog more comfortable.

LIGAMENT OF THE HEAD OF THE FEMUR: Attaching to the head of the femur from the center of the hip socket is a tough fibrous ligament called the Ligament of the Head of the Femur.  If this ligament is stretched or torn, the hip joint will be less stable . . . and this is exactly what happens to dogs with dysplasia.  In fact, some of the first changes to take place in young dogs developing hip dysplasia occur in this ligament especially if the muscle mass of the pelvis is underdeveloped.  The ligament swells, develops tiny tears and stretches.  In advanced CHD this ligament can totally break down and cause more harm than good.

JOINT CAPSULE: This tissue, which if you could hold it, would feel like the wall of a thick balloon   It surrounds the joint and produces synovial fluid to nourish and lubricate the joint cartilage.  In addition, the joint capsule provides some support to the joint.

In dysplastic joints the capsule becomes irritated, stretched, and scarred.  In advanced cases the capsule will lose its elasticity and inhibit a full range of motion in the joint.  A large percentage of the pain associated with hip dysplasia originates from inflamed nerve endings in the joint capsule so any pathology here will have a noticeable affect on the dog.

CARTILAGE: The surfaces of the head of the femur and the acetabulum are covered with what is termed hyaline cartilage.  In a dysplastic joint the points of pressure and the amount of pressure applied to areas of cartilage surfaces are abnormal.  The cartilage is being asked to do things it physically cannot accomplish, so it changes or disintegrates as a response. The changes range from thickening in abnormal areas to thinning in others.  Sometimes the pounding it gets erodes the cartilage down to the underlying bone!  The outcome is more pain and discomfort, more inflammation, more calcium deposits from inadequate healing attempts and eventual breakdown of the joint as a unit.  Nutriceuticals such as Chondroitin Sulfate and Glucosamine may be effective in aiding the repair and maintenance of this articular cartilage.

BONE CHANGES: Since bone is alive it responds to stress and grows in a manner that tends to distribute weight loads evenly.  As a result of posture changes brought on by discomfort, the dog's weight bearing forces stress the bone in  unnatural ways.  The bone does what it is supposed to do as a response and changes its shape.  The bone doesn't know doesn't know that the shape it changes to is abnormal.

Ultimately, this abnormal shape to the thigh bone and acetabulum create more difficulty with stability and a vicious cycle ensues that spells trouble for the dog.  See the images below for a comparison of before/after bony changes.  The final outcome of bony remodeling in unstable hip joints is Degenerative Joint Disease.

SIGNS OF CHD IN YOUNG DOGS: What you will see first is a pup that runs with both back legs nearly together, almost like a rabbit would run.  After exercise the pup will be reluctant to rise, will sit back as if unsteady and will have difficulty climbing stairs or inclines.  The pup might look slightly underdeveloped in the rear quarters.   When it stands the rear legs may not be parallel, but rather too near each other at the hocks (ankles) called "cow hocked".

You might notice a boniness to the pelvic area from lack of good muscle development.   Another hint of trouble is an inability to extend the leg backward very far (decreased range of motion).  Note: Many pups rest or sleep in a frog-like position with knees extended out to either side - this is a good sign and shouldn't alarm you.  

In severe cases of dysplasia, the young dog will rock forward to support more weight on the front legs (which can create trouble in the shoulders and elbows).  When dogs do this it seems as if they are tip-toeing or walking very lightly on their rear legs.   A dysplastic pup will be reluctant to jump or "stand up" on its hind legs.  Signs usually being between five and eights months of age.  But remember, as we learned above, some dogs do not show any signs at all of hip joint degeneration until mature adults.

AN INTERESTING CASE:  Here is a classic example of why it is so important to take a radiograph of the sire and bitch prior to breeding.  In this example the owner had a two year old male Golden Retriever that was totally healthy by any observable standards.  It ran, jumped, swam and had never showed any kind of lameness.  The owner had the dog x-rayed and guess what?  The film displayed severe abnormalities in the left hip joint.  Were the changes due to a genetic propensity for hip joint abnormalities?  Or was this actually due to an injury early in the pup's life that impacted the proper growth of the joint structures?  No one can say for certain.  But IF the abnormal hip was due to genetic determiners why take a chance that, if bred, the litter might have even worse hip joint conformation?  The owner decided not to breed the dog.

SIGNS OF CHD IN OLDER DOGS: Some dogs with dysplasia escape pain or simply accept it as a fact of life and don't complain until degenerative joint disease sets in.  Affected dogs will sit rather than stand, have trouble arising, run with the rear legs together and not be able to keep up any more on Sunday walks.  Every veterinarian has been mystified on occasions where an x-ray of an older dog, who only recently seemed to be having hip trouble, reveals extensive degenerative changes in the hips due to long term dysplasia.

It is very important to keep this fact in mind: A dog can appear normal and yet have hip dysplasia.  Just because a four-year-old dog isn't showing signs of trouble is not sufficient evidence to state "it couldn't possibly have hip dysplasia".  I have heard supposedly responsible breeders make that statement and it takes lots of convincing to get them to believe otherwise.

If you are involved with a breed in which CHD has been reported, and you wish to improve the breed as well as have happy owners of your pups you must know if your breeding stock is prone to CHD.  And neither you, your cousin, the mailman OR your veterinarian can tell if your dog has CHD unless some basic guidelines are followed.

DETERMINING THE PRESENCE OF CHD: Dogs with obvious signs of CHD (hip soreness, difficulty arising or climbing inclines, muscle atrophy over the rump, limping) are not a challenge to confirm as such.  So this discussion will apply more to the dog that seems to be normal but you are either not sure or need to know for breeding or training/working reasons.  The minimum data required is a pelvic x-ray taken under anesthesia . . . PERIOD!  You MUST have the x-ray to know if the dog is normal!   

PennHIP: (University of Pennsylvania Hip Improvement Program)   See an entire article about PennHIP here.
Commercially available since 1993, this procedure has been and was developed as an objective method of evaluating dogs’ hip structure.  It evolved as a direct result of the subjectivity factors and age constraint (maturity) limitations inherent to evaluation and certification of dogs by the OFA and other screening programs.  PennHIP research published in peer reviewed journals has shown that different breeds have different susceptibility to osteoarthritis.  Therefore, in PennHIP evaluations each breed is compared to its own. Only PennHIP certified veterinarians can do the PennHIP evaluation but many veterinarians are becoming certified in this procedure.  

Why is anesthesia required in order to have the dog radiographed?  To have an x-ray that yields the information you're trying to discover the dog must be perfectly relaxed.  Because the position required to take a diagnostic x-ray is a somewhat unnatural one, even very gentle, cooperative dogs cannot relax enough to be x-rayed properly.  See the x-ray on the right. It is a great example of poor positioning. (Click on it to enlarge.) The dog is tilted to its left (to our right) and the view we see of the structures is imbalanced.  One hip looks OK and the other bad but in reality this view is worthless. Nothing is more frustrating for the veterinarian than to have an owner say "I need to know if this dog has any signs of hip dysplasia.  Take an x-ray, but I don't want you to use anesthesia; this dog will do anything you tell it to do, so an anesthetic isn't necessary."  Unless at the time of exposure of the x-ray, the dog is positioned precisely, with no movement, the x-ray will not be credible.  You won't get the information you need!  Your veterinarian will look for an x-ray image that looks like the nice, normal hip at the beginning of this article.

Another great advantage of anesthesia is that the veterinarian can only then palpate and manipulate the hips to actually feel the degree of looseness.  Also, the tension of the Pectineus Muscle is best assessed under anesthesia.  Any grating or grinding from calcium deposits along the hip joints can be evaluated better than attempting to do so on an awake patient.  If you need the information, the dog needs the anesthetic.

If the pelvis is tipped only slightly to one side or the other, one hip can appear normal that isn't and one can appear dysplastic that isn't!  To complicate things, 10% of dysplastic dogs will be affected in only one hip!  Better do the x-ray right!

The importance of radiography cannot be overstated.  It can be done early, say five or six months of age, if dysplasia is suspected.  If the results are questionable, reserve breeding until a time when the x-rays are conclusive.  Generally, by the time the dog is full grown the x-rays will properly reveal the status of the hips.  The OFA (OFA.org) will not classify hips in dogs until they are two years of age.

The advantage of radiography in a younger animal is that if you plan on breeding it you can eliminate fruitless time and financial and emotional expense related to breeding if the x-rays show unquestionable hip dysplasia.  There have been many disappointed, depressed dog owners whose expectations for breeding were high and were shocked back to reality when their two-year-old dog showed x-ray evidence of dysplasia... two years of planning, training and dreams of great litters down the tube.  If only the parents had been x-rayed. If only preliminary x-ray were taken eighteen months ago.  Again, the advantage of the PennHIP procedure is obvious since dog over 4 months of age cane be evaluated.

It is very sad indeed for any pet owner to see their special pal affected by the discomfort and mobility problems associated with Canine Hip Dysplasia.  Fortunately, armed with knowledge and forethought, highly selective breeding is your best defense against CHD.

For your inspection you can click on any of the images below to see
a full sized photo in a new window.

Normal Hip Joint	Severe Hip Dysplasia and Degenerative Joint Disease	Dysplastic in both hips, one is subluxated	Osteoarthritic hips due to hip dysplasia	These hips are almost dislocated they are so loose fitting
Moderately dysplastic hip	Crippling arthritis	Not bad but not good either	A normal cat hip image	Poor positioning for an accurate diagnosis

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Canine Hip Dysplasia

By Wendy C. Brooks, DVM, DipABVP
Educational Director, VeterinaryPartner.com 
http://www.veterinarypartner.com

Hip dysplasia is a common condition of large breed dogs and many dog owners have heard of it but the fact is that anyone owning a large breed dog or considering a large breed dog as a pet should become familiar with this condition. The larger the dog, the more likely the development of this problem becomes, particularly as the dog ages. The following is a review of this disease. If you have additional questions, please send them through the Ask A Vet feature on the home page.

So What is Hip Dysplasia?

The term dysplasia means abnormal growth, thus hip dysplasia means abnormal growth or development of the hips. Hip dysplasia occurs during the growing phase of a puppy, usually a large breed puppy, and essentially refers to a poor fit of  the ball and socket nature of the hip. The normal hip consists of the femoral head (which is round like a ball and connects the femur to the pelvis), the acetabulum (the socket of the pelvis), and the fibrous joint capsule and lubricating fluid that make up the joint. The bones (femoral head and acetabulum) are coated with smooth cartilage so that motion is nearly frictionless and the bones glide smoothly across each other’s surface. 

The femoral head (the ball in the ball and socket joint) is outlined in yellow. The acetabulum (the socket in the ball and socket joint) is outlined in red. The femoral head ball is designed to fit inside the acetabulum socket.

When a dog has hip dysplasia, the ball and socket do not fit smoothly. The socket is flattened and the ball is not held tightly in place, thus allowing for some slipping. This makes for an unstable joint and the body’s attempts to stabilize the joint only end up yielding arthritis.

normal hip - femoral head fits snugly inside acetabulum	early stage hip dysplasia - note space between femoral head and acetabulum

If this Disease Starts in Puppy hood Why are Most Affected Dogs Elderly?
Actually, there are two sets of patients typically affected by hip dysplasia. The first group is the adolescent dog, typically 6 to 18 months of age. The radiograph on the right shows the hips of such a patient. This dog has hip dysplasia but has not yet developed arthritis. Note the shallow hip sockets. This dog was brought to the vet’s office for signs of discomfort. Radiographs were taken and hip dysplasia was discovered. Many dogs with similar radiographs will not be in pain and thus will not end up coming to the vet for an evaluation. These dogs show up as elderly dogs, after they have been walking on their poorly formed hips for many years. After many years, bony build up along the margins of the socket, mineralization of the joint capsule, cartilage wear, and inflammatory change in the joint (i.e., degenerative arthritis) has become painful and now the dog comes to the vet for an evaluation.  

bad hip dysplasia

Why Do Some Dogs Have Pain at a Young Age While Others Don't Have Pain Until They're Old?
Obviously different individuals may have different degrees of dysplasia. A dog’s weight makes a difference (a lighter dog can tolerate a more abnormal hip joint). The muscle mass supporting the joint is greater in a younger dog and helps reduce the stress directly on the bones. Still, some dogs have truly shocking radiographs and virtually no symptoms while others show relative subtle changes and are very uncomfortable. We don’t know why there isn’t a better correlation between radiographs and actual pain.

How Can an Owner Tell if their Dog is Having Discomfort?
Do not expect a dog with dysplasia (or any other chronically painful condition for that matter) to cry or whine in pain. Instead discomfort is shown with reduced activity, difficulty rising or lying down or going up stairs. A characteristic swivel of the hips is seen from behind and classically stairs are taken in a bunny hop fashion.

What Causes Hip Dysplasia?
The primary cause of hip dysplasia is genetic but inheritance of this trait is not as simple as a dominance/recessive relationship like we study in high school biology. Normal dogs can breed and yield dysplastic offspring as the condition may skip generations. Until a test based on the actual DNA can be developed, the best we can do to prevent this disease is to breed only dogs with normal hips (a challenge since often dogs are not apparently dysplastic until they have already started a breeding career.)

Nutritional factors are also important in the development of hip dysplasia. For example, it has been popular to try to nutritionally “push” a large breed puppy to grow faster or larger by providing extra protein, more calcium, or even just extra food. Practices such as these have been disastrous, leading to bones and muscle growing at different rates and creating assorted joint diseases of which hip dysplasia is one. One study showed that when puppies of hip dysplasia prone breeds were allowed to free feed, two thirds went on to develop hip dysplasia while only one third developed hip dysplasia when the same diet was fed in meals. Another study showed German Shepherds were nearly twice as likely to develop hip dysplasia if their adult weights were above average. Studies such as these have led to the development of puppy foods designed for large breed puppies, where the optimal nutritional plane is lower than for small breed puppies.

How Can I Find out if My Dog has Hip Dysplasia?
There are two reasons to pursue testing: to explain a dog’s discomfort/rear weakness or to screen a dog for breeding purposes. If a dog is not going to be bred and is not in any apparent discomfort, there may be no benefit to looking at the conformation of the bones in a radiograph except possibly to look back at a future time to get a sense for progression of bony changes.
  
The first step in diagnosis is an examination. Your veterinarian will likely extend the dog’s hind leg backward to check for pain. (Hip dysplasia causes pain on hip extension.) The dog may be asked to walk around to demonstrate the possible hip swivel. Another test involves having the dog lie on its back with a hind leg perpendicular to the body. As the leg is moved away from perpendicular to the body, a dysplastic hip will generate a pop as the femoral head slips to the center of the acetabulum. This pop, which can be felt if one’s hand is resting on the hip during the exercise, is called an Ortolani sign. You may hear this term used as hip dysplasia is discussed.

in a dog suffering hip dysplasia, femoral head has moved away from acetabulum	Ortalani sign: an audible pop is heard as the femoral head slips back to the center of the acetabulum

To find out for sure about dysplasia, radiographs are necessary and this generally involves some sort of sedation to minimize the patient’s discomfort as their hips are properly positioned for the picture. Sedation also helps the veterinary team control the dog’s position better so they can minimize the number of radiographs needed in order to get one good diagnostic view. The classical view is called a VD pelvic view where the dog is held on its back with its legs straight out. This shows the seating of the two femoral heads as well as any bony changes indicating arthritis. This is the view required by the Orthopedic Foundation for Animals for registration.

What is OFA Registration?
When purchasing a puppy, particularly one of a larger breed, often the parents will be listed as “OFA Good” or “OFA Excellent.” What this means is that the breeder has had the hips of the dog’s parents certified by the Orthopedic Foundation for Animals. The OFA is an organization with a goal of reducing the incidence of hip dysplasia (though now it is also possible to obtain certification for elbows, thyroid function, and other issues). The idea here is that a dog for breeding can have radiographs taken at age 24 months. The radiographs are sent to the OFA for review by several independent radiologists where they are graded. Hips that are rated as good or excellent receive a registration number.  Offspring of OFA-certified parents would be less likely to develop dysplasia themselves, however, it is important to realize that a dog with excellent hips at age 2 may not have such excellent hips at age 5, 7, or 10. OFA certification is no guarantee that a dog will not develop hip dysplasia symptoms in the future and does not guarantee that the offspring will not develop hip dysplasia.

What is PennHip Registration?
Many people with potential breeding dogs do not want to have to wait two years for OFA registration. The University of Pennsylvania Hip Improvement Plan, developed by Dr. Gail Smith, allows for another way to predict if a dog will develop hip dysplasia. For PennHip certification, the veterinarian taking the radiographs must receive special training and special equipment is necessary. The pet is anesthetized and two radiographs are taken: one with the femoral heads compressed (pushed into the acetabula as far as they will go) and one with the femoral heads distracted (pulled out of the acetabula as far as they will go). A measurement called a distraction index is calculated from these radiographs,  the idea being that a tighter fitting hip (one allowing less distraction) is less likely to develop dysplasia. Each dog breed has a different range of distraction indices that are considered acceptable. Puppies can be certified as young as 16 weeks of age with this system.

view in distraction	view in compression

Is Surgery the Best Treatment for Hip Dysplasia?
There are many surgical options for hip dysplasia and it is important to understand which patients benefit from which surgery. Some surgical procedures are controversial and some are not. All will entail a recovery period as well as expense. Often both hips need not be treated surgically; treating one hip is often enough to yield good results. Hip surgery is expensive, usually $2000 to $3000 in the Los Angeles area. If you are considering surgery for your dog, these are the procedures to know about:

  Triple Pelvic Osteotomy
This surgery is appropriate for young (age 8-18 months) dogs with dysplasia but without degenerative arthritis changes. This means that there is a window of opportunity for this surgery and if the dog develops arthritis or becomes too old, it will be too late for this surgery to be performed. In this surgery the ill-fitting acetabulum is essentially sawed free of the rest of the pelvis, re-positioned for a tighter fit on the femoral head, and then plated back into place.

Three cuts are made to free the acetabulum from the pelvis

Many times surgery on one hip leads to positive changes in the other hip so that surgery on the second hip is not necessary. Alternatively it is possible to do the TPO on both hips if it seems clear that ultimately both will need surgical correction. This is a surgery that requires a board certified surgeon or a surgeon with extensive orthopedic experience. After care involves a good 3 to 4 months of exercise restriction. No leashed walks are allowed for 2 months except to go outside for elimination.  
 
  Femoral Head/Neck Ostectomy
This surgery is commonly referred to as the “FHO” and is best used for smaller dogs (50 lbs or less) or very active dogs. Here, the femoral head is cut off and removed, allowing the joint to heal as a false joint (just a capsule connecting the two bones but no actual bone to bone contact. If the dog is not carrying too much weight, a false joint is strong enough. If the dog is very active, a false joint will form quickly. The pet typically does not want to use the leg for the first 2 weeks but should at least be partially using the leg after 4 to 6 weeks. The leg should be used nearly normally after a couple of months. Many veterinarians are well experienced with this surgery and often a specialist is not needed. This surgery is typically substantially less expensive than the other procedures.

femoral head before FHO

femoral head cut off after FHO

Total Hip Replacement
This procedure is for dogs with established degenerative hip changes. For these dogs, the best choice may be to simply replace the hip (or hips) with a prosthetic hip. This procedure may sound radical but it has been commonly performed for nearly 20 years in dogs with great success. This is a highly invasive procedure, obviously, and infection must be avoided at all costs (no skin disease can be present in the skin over the hips, extra precautions for sterility are used). In other words, when complications occur they have potential to be disastrous. Complications have about a 10% incidence. Expect about 3 months of exercise restriction after this procedure. Usually only one hip receives surgery at a time. Often only one replacement is needed and the pet does well enough not to need surgery on the other side.

x-ray of a bilateral (both hips) total hip replacement

  DARthroplasty
“DAR” stands for dorsal acetabular rim. In this procedure, bone grafts taken from other areas of the pelvis are used to build a longer rim on the acetabulum so that the femoral head will have a deeper socket in which to fit. This procedure is best done in dogs that are too old for triple pelvic osteotomy or have just started developing degenerative arthritis. This is a fairly new procedure in the hip dysplasia arena and thus somewhat controversial. Long term success (i.e., how patients do when they are old) is not really known as the procedure has not been performed long enough to collect results from a large number of patients. A specialist is needed for this surgery.

Juvenile Pubic Symphysiodesis

This surgery is performed on young puppies before age 5 months, so it is generally done as a preventive procedure before it is known if the puppy will indeed have dysplastic hips. The pubic symphysis is the cartilage seem connecting the right side of the pelvis to the left side. As an individual matures, this cartilage converts to bone and the two halves of the pelvis fuse permanently. This surgery prematurely seals the symphysis, which in turn results in rotation of the developing hip sockets into a more normal alignment. While studies show promise, because this procedure is done on puppies who do not yet actually have hip dysplasia, it is hard to evaluate success.

What Non-Surgical Treatment is Available?
Non-surgical treatment of hip dysplasia is essentially the same as non-surgical treatment for any other type of arthritis. There are nutritional supplements to help repair cartilage, pain medications, and anti-inflammatory medications. Physical therapy and massage are also important and helpful in non-surgical joint therapy.

Copyright 2005 - 2010 by the Veterinary Information Network, Inc. All rights reserved.
This work was originally published by Veterinary Information
Network, Inc. (VIN) and is republished with VIN's permission.

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Hip Dysplasia, the LMX Formula

by Tina Barber

Many German Shepherd lovers have seen, known, or loved a dog that suffered great pain, even had to be put down at a young age due to Canine Hip Dysplasia (CHD). Though we love this huge breed, the question begs to be asked-Is it worth the risk to purchase and fall in love with a dog only to watch is struggle to stand up when it should be in the prime of its life?

Through the lifetime dedication to her dogs, Tina Barber has created a breed that holds all the traits of the German Shepherds of old, without one critical characteristic-bad hips. Too good to be true? No. Through her Litter Mate X-ray program or LMX, she has answered the prayers to every brokenhearted shepherd owner by producing Shiloh Shepherds that are 97% dysplastic free.

Let's start at the beginning. First, in simple words, what is Canine Hip Dysplasia? Canine Hip Dysplasia (CHD) is a truly crippling disease. It causes weakness, deterioration, and ultimately arthritic hips in dogs and is considered a genetic trait. Understanding that this condition is primarily genetic is the key Tina has used to produce Shiloh's from her kennel who are 97% dysplasia free.

It is simple genetics to understand that an inherited trait is a characteristic that is passed from parents to offspring, each parent offering fifty percent (50%) of the offspring's total genetic makeup. We have all said something like You have your mother's blue eyes. That's simple genetics. So, the knowledge that CHD is genetic is understandable, but how do we avoid the passage of that trait? The answer seems easy, know the parents. If mom and dad are clear of hip dysplasia, the puppies will be fine-right? Wrong! It is easy to spot a genetic trait that both parents display, back to the example of blue eyes. But what about that child that has those same beautiful blue eyes when both parents have brown? Here lies the key Tina Barber has found to practically rid the Shiloh Shepherds of hip displays ia.

Tina's LMX program (Litter Mate X-rays) has taken the genetic study of her Shiloh's to an entirely new level, and is a unique program to Shiloh Shepherds. Many understand the concept of dominant and recessive genes, again basic genetics. Dominant is what you can see (known as phenotype) and recessive is what you have but don't see (genotype). Why is this information important? Just because the parent dogs don't, themselves, have hip dysplasia does not mean they don't carry the gene. So, can this gene show itself through puppies if it does not show in either parent? You bet.

For each dog you see, there is also what can be thought of as a shadow dog. The traits of a dog that is in each dog, but cannot be seen. Therefore, an offspring of a dog that does not have hip dysplasia can suffer from CHD. The first situation to illuminate this point-- each parent does not have the phenotype for hip dysplasia, yet carry the genotype. Therefore, both parents carry that recessive. As a result, a dysplastic puppy can be born from parents that do not themselves have hip dysplasia. Another scenario, a puppy may not display actual dysplasia, but is a carrier since it got the recessive gene from mom or dad. Now, this puppy is ultimately bred with a dog who also carries the recessive, again, you have a dysplastic puppy.

This knowledge would solve it all if we could determine the genotype, or recessive qualities of each parent dog. Unfortunately, that is not possible. However, Tina discovered if x-rays were taken of not only dogs that were intended for breeding, but of all litter mates born, those genotypes or recessive genes would reveal themselves allowing to only breed those dogs who did not carry the gene causing hip dysplasia. This brings out that shadow dog through x-rays. If a parent dog does not have CHD, but is passing on the gene, that dog is no longer used for breeding. Without data on litter mates, it would be impossible to reveal the recessive gene.

This is not theory- data is the key to Tina's research, but it is also the key to proving her success. Numbers don't lie! To restate the most impressive statistic, her kennel is 97% free of hip dysplasia. How does this compare to today's German Shepherd?

The GSD is at 16% dysplasia with only 1% of dogs being x-rayed. The bad x-rays are not being reported. So the gene for those bad hips simply passes on to the next generation. It is stated by the OFA that hip dysplasia can only be reduced by selectively breeding for normal hips! Since it is now a fact that CHD is caused by inheritance, it is imperative to know about your dog's entire gene pool!

There is a philosophical difference between puppy producers and breeders. The end result of a true breeder is to continue to better the breed and produce puppies that are products of optimal specimens. They are after more than selling puppies for high dollars. You don't have to be a huge puppy mill to behave in a manner that is harmful to dogs and future owners. It is also the small breeders that over breed, don't monitor genetics, and allow substandard examples of a breed to reproduce and allow flawed genetics to continue pass to litters that should never be born. If a puppy is born with less than desirable traits, that puppy should not be bred. We are not dealing with a minor genetic flaw; we are dealing with hip dysplasia-a trait that can only cause pain and suffering to the dog. The LMX program is NOT based on theory. The LMX program has the backing of facts proving it is a successful method in ridding dogs of this painful condition!

The dedication to the LMX program extends back to 1962, decades of genetic data gathering. Although it is impossible to see that shadow dog in Tina and her breeders' dogs, they have a valid blueprint due to the knowledge of a vast amount of ancestors and puppies born to their dogs. Since the Shiloh has entered the Rare Breed world, a computer system as been designed that provides information on dominant and recessive faults and virtues. The LMI program, or Litter Mate Information, is only an extension to the original LMX program that has been the key to reducing hip dysplasia in the Shiloh Shepherd.

There are some key factors that make this program effective, or ineffective if not completed correctly. There can be no conclusions drawn from incomplete data. For example, if a litter only has 3 puppies, all with good hips, the assumption cannot be made that had the litter been larger there could have been pups with bad hips. In such a case, it is vital to research the litter mates of the parents of the three puppies. The progeny they produced will be helpful to complete the data. Additionally, research into the siblings and ancestors, preferably 7 generations, is the only way to complete the genetic picture. Simply stated, the more genetic pieces one can collect, the more the shadow dog can come to light.

Another key is quality x-rays. If poor x-rays are sent to the OFA (Orthopedic Foundation for Animals)a perfectly healthy and genetically strong dog could be classified moderately dysplastic. This misinformation can lead to excluding dogs that have the potential to produce outstanding litters. Shiloh's tend to have a tendency toward mild subluxation a young age. If this dog is x-rayed a year later by a more proficient clinic ,he could certainly receive a good OFA rating. Recent research with Penn Hip - developed at the University of Pennsylvania Veterinary School, has proven this. This method takes x-rays from a different position than OFA x-rays. Many dogs that have been rejected by OFA have receive good ratings through this new system. Using both systems will allow a better understanding of the dog's true hip quality. Documentation is paramount. In order to eliminate CHD guessing cannot be an option. The collection of valid data not only protects from poor genetics, but will protect an excellent dog from falling by the wayside and not passing on quality genetic traits due to poor data.

In conclusion, the LMX program helps remove the wondering of what genetics a dog may process but are not visible. It goes far beyond mom and dad's traits. It tracks traits down through siblings and ancestors. It is thorough documentation in tracing key genetics and has allowed breeders to expose that shadow dog. The program can only be effective, however, if breeders and owners participate in the program. Those who love the breed and want the continued success of excellent hips must cooperate. Anyone wishing to purchase a Shiloh Shepherd must do their research. The I.S.S.R breeders are committed to this breed and do all they can to promote these amazing dogs. They follow the strict guidelines set fourth by Tina and work as productive team to maintain high standards for each and every dog. This cooperation in the LMX program allows the I.S.S.R Shiloh's to live a long and healthy life, free from the crippling effects of hip dysplasia.

Tina Barber has been involved with German Shepherd Dogs all of her life. She started her own training kennel and breeding program in 1962. Thus began her quest to develop the ultimate companion. Her struggle and success is beautifully documented in this exciting book.
The Shiloh Shepherd is still under development but stands as a model of what pure breeding is all about. The book and the website reveal the breed founder's vision. Tina's web site can be viewed at www.shilohshepherdstory.com You may contact Tina at MaShiloh@shilohshepherds.info  

Copyright September, 2006 - 2010

reprinted with kind permission from Tina Barber

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Prevention of Hip Dysplasia

One significant factor in the development of hip dysplasia is the nutritional load, especially in growing large-breed dogs. Feeding high-calorie puppy food promotes rapid bone growth and weight gain. The soft-tissue components of the hips don’t mature and grow at the same rate as the bones. Often, by the time these soft-tissue components catch up, there can be bony deformity, due to a period of unstable hip joints. By switching to the lower-calorie large-breed puppy growth food, or switching to adult dog food after fourteen weeks of age, the growth rate can be slowed, and all of the components of the hip joints can mature in unison. The adult size of the dog is genetically determined, and reduced-calorie feeding will only alter the age when this size is attained.

Excessive jumping and compaction activity on the hip joints during the critical growth periods prior to skeletal maturation can also affect the degree of later dysplastic development in genetically predisposed dogs. Changing feeding protocols and managing excessive environmental stress will probably not prevent hip dysplasia in genetically predisposed dogs, just as reasonable overnutrition and activity will probably not cause hip dysplasia in genetically normal dogs. However, modifying feeding practices can alter the degree or severity of clinical signs in affected dogs. Breeders should evaluate prospective breeding dogs that have been raised under fairly uniform conditions, so that any differences between them are due to heredity, not environmental influences.

There are no scientifically proven drugs, vitamins, or food supplements that will protect the hips of genetically predisposed dogs from developing hip dysplasia. Joint-formula compounds (including glucosamine and chondroitin) are shown to diminish hip-joint pain in dogs. Nonsteroidal anti-inflammatory drugs (such as aspirin, Rimadyl, and Etogesic) are also effective for treating joint pain. Owners should discuss with their veterinarian which medications are appropriate for their dog’s condition. Avoiding overfeeding, and maintaining a lean body weight will also diminish hip pain in affected dogs.

Author Unknown

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Hi, Geoff –
Just thought you might enjoy seeing a picture of our beloved GSD (attached).  His name is King von Borgersen, his DOB is 11/26/94, he is half Heidelberg/ half American GSD, he had his left hip replaced 2/17/00 and has been good with respect to that ever since, and is doing well with the myriad of heart medications.  (I wish that my father had as good a cardiologist when he was alive!)
Thank you,
Joan

Hip Dysplasia- The Latest News	The Cause of HD	Dealing With Wrong Ideas About Hip Dysplasia	Options for the Dysplastic Dog
Vitamin C and Hip Dysplasia		Exercise and the Dysplastic Dog

Hip Dysplasia Surgeries

Femoral Head  Ostectomy (FHO)	Triple Pelvic Osteotomy (TPO)	Total Hip Replacement (THR)	Excercise and the Dysplastic pup
Testimonial Sadie's Story	Testimonial Lacy's Story	Motion Capture Hip Dysplasia	Vet-Stem Regenerative Cell  (VSRC) Therapy
Hip Dysplasia John C. Cargill, MA MBA, MS  Susan Thorpe-Vargas, MS	Ed Frawley's Leerburg Video site features The Importance of Proper Positioning for Canine Hip X-Rays with diagramatic radiographs.	Juvenile Pubic Symphysidesis (JPS) Preventing the Degenerative Effects of Hip Dysplasia In Dogs	Relationship of Nutrition to Developmental Skeletal Disease in Young Dogs
Ester-C:  Miracle Cure for Hip Dysplasia???	Femoral Head and Neck Resection In A Dog	Darthroplasty	How to Keep Your Dog from getting Depressed after Surgery
Memory Foam Pet Beds	Hip Dysplasia Scheme	Pilates for pooches	Stem Cell Breakthrough for Suffering Pets
Integrative Treatment	New Words in The HD Dictionary

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