Canine Hip DysplasiaWHO GETS IT?
The hip joint is a ball-and-socket joint. The ball part is called the femoral head, and the socket part is called the acetabulum. In very young dogs there are big growth plates in both parts - this is what gives a tissue as hard as bone the ability to change shape. You can see these growth plates in the x-ray to the left. Growth plates look like just spaces between the bone pieces. This x-ray is of an 8 week old Great Dane puppy. As dogs grow through puppyhood, pressure from their own body weight and normal activity cause both parts of the joint to form properly to itself. The femoral head rounds out, and the acetabulum gets more rounded and cup shaped. In a puppy with hip dysplasia, the femoral head is not held tightly into the acetabulum. The hip joint is looser than it is supposed to be - we call this joint laxity. Because of this laxity, the pressures from body weight and activity (that are supposed to go up the leg and directly into the joint) are instead spread over a larger area. The looser the joint, the larger the area for pressure to be spread over, the less rounding out happens to both the femoral head and the acetabulum. The result is a "flatter" joint. Because of this flatter shape and the joint laxity, the joint now moves abnormally too. Over time all of these changes will lead to arthritis in the affected hip joint.
Notice that I am showing you x-rays to explain this. The diagnosis of canine hip dysplasia REQUIRES that x-rays be taken, usually under heavy sedation or even general anesthesia.
Good, reputable breeders of these at risk breeds are working very hard to get hip dysplasia out of their bloodlines. Puppy mill breeders could care less if their dogs are healthy or not. If your breeder (of a breed that is prone to hip dysplasia) has never heard of the Orthopedic Foundation for Animals and has not had the parent dogs screened and certified for hip dysplasia,you should probably look elsewhere for a puppy. It is possible, however, to end up with a puppy who has hip dysplasia but was born to two parents who did not. This is because it is a genetic recessive condition. If both parents carry only one canine hip dysplasia gene, then neither dog will show the disease - their hips will look good. But breeding them will result in a 25% chance of a pup who gets both canine hip dysplasia genes, one from each parent, and so will have hip dysplasia. It's important that the breeder knows if this happens, so that those parents can be removed from the breeding program. Never EVER breed a dog who actually HAS canine hip dysplasia.
If you do end up with a dog or puppy who has canine hip dysplasia, keep in mind that there are treatments, and even some "fixes" available to help. If you suspect that your young pup has dysplastic hips, then a surgery like a pubic symphyseal fusion or a triple pelvic osteotomy can be done. Which procedure is done depends mostly upon the age of the puppy - pubic symphyseal fusion is done for very young pups (typically 3-4 months old), while triple pelvic osteotomy is the surgery of choice for older pups (usually 6-12 months old). Both surgeries cause the acetablulm to be rotated so that it covers and seats the femoral head more firmly. If you have an older full grown dog, maybe with arthritis, that you want to help in terms of pain relief, then either a total hip replacement (for larger dogs) or a femoral head and neck ostectomy (for dogs weighing less than ~30 pounds) can be done. These are both generally done in younger badly affected adult dogs, not those dogs who are already in their senior years. The total hip replacement replaces both acetabular and femoral head joint surfaces with artificial implants. The femoral head and neck ostectomy removes the femoral head and neck completely, with no replacement provided. A false soft tissue joint develops here, and as there is no longer bone grinding on bone (as with arthritis), the pain is greatly reduced. All of these surgical procedures are specialty type surgeries - you want a doctor who specializes in surgery to do them, not just a regular veterinarian. All of these surgical procedures carry a pretty price tag too. And finally, all of these surgical procedures have potential risks and complications associated with them. Discuss it all with your veterinarian! If surgery is not an option for you or your dog, then go to the Arthritis in Dogs pages to review all of the medical options for treating chronic arthritis pain. There is a lot more that you can do for them, besides surgery! In theory, we should be able to breed canine hip dysplasia out of the dog population. Remember though, if you have a dysplastic puppy or dog that various treatments are available. Do what is within your means to help your friend! The information presented here is not meant to replace the advice of your own veterinarian! A valid veterinary-client-patient relationship (created when you take your pet to see your vet) is essential to providing excellent individual pet care. If your pet is ill, call or go to your vet or an emergency veterinary hospital!
Go back to Dog Health Problems from Canine Hip Dyspalsia.
Last updated 02/16/10.
|
Canine hip dysplasia is a genetic based disease. Breeds with the highest incidence (likelihood) of hip dysplasiainclude German Shepherds, Golden Retrievers, Labrador Retrievers, Rottweilers and St Bernards. If you are interested in having one of these breeds, be sure to ask about this disease. If you are getting a puppy, ask if the parents are both OFFA (Orthopedic Foundation for Animals) certified. If you are getting an adult dog, ask if any hip screening x-rays have been done, and if so ask to see the medical report.
In order to understand canine hip dysplasia, you first have to understand the anatomy of this joint and how it forms as a puppy grows. 
This x-ray is of a 9 month old Golden Retriever. We can see significant changes in these hip joints. The hip joint on the left side looks fairly OK - the femoral head is somewhat rounded (could be better), and sits within the cup shaped acetabulum. The joint on the right though is much different. The femoral head on the right side isn't even sitting within the acetabulum - this is a pretty badly dysplastic hip joint. 
This next x-ray shows what hip dysplasia leads to. This is what severe arthritis looks like in a badly dysplastic hip joint. The acetabulum and femoral head are both very flattened, there are lots of little bone spurs, and the femoral head even has a moth-eaten appearance to it inside. This is pretty advanced and severe arthritis, and is likely pretty painful for the dog.
