The Importance of Good Positioning on Canine Hip X-rays
Notes from the Tufts Genetics Breeders Conference
- September 27th-29th, 2013
Chronology of Hip Dysplasia Development in a Cohort of 48 Labrador Retrievers Followed for Life
- another article on the subject
I would like to thank Dr. Jane Brakken for help with my dogs and
allowing me the use of her x-ray room to take these photos.
The purpose of this article is to teach the average dog owner how to determine if a hip x-ray is done properly on their dog’s hips. The article will demonstrate correct positioning and poor positioning. It will show 2 different sets of x-rays done on the same dog on the same day. One set has good positioning, the second set has poor positioning. You will see that with poor positioning, a dogs hips can look worse than they actually are. You will also see that no matter what you do with positioning you can never make a bad hip into a good hip.
The photo of the hip x-ray above (labeled good positioning) was done on a 10 month old German Shepherd from my kennel. While the dog is slightly angled on the x-ray plate, the positioning for the hips is pretty good. The photo below (the same photo as above) shows the various points on an x-ray to look at to determine if the dog was positioned properly.
Because this article is directed to the general public, I will not attempt to use the proper medical names for a lot of the terminology in this article.
The first thing to look at in an x-ray is to see if the legs come straight down from the hips with the knee caps square and looking alike. We don't want to see one leg straight and the other going off at an angle.
The above photo has 3 sets of colored arrows (green, yellow and red).
The green arrows above point to the bone that the hip socket is built into. These bones almost look like wings. You will notice that you can see more of the wing on the right than the wing on the left. When the position is 100% perfect, both wings will look exactly alike.
The yellow arrows point to holes in the bone structure. When the body positioning is correct the 2 holes on the left side are the same shape and size as the holes on the right side. The positioning is good on this dog, but not 100% perfect. That's why the holes on the right are slightly different than the left. This is most noticeable in the lower right hole being smaller than the left side lower hole.
The red arrows above are the first things I look at when examining an x-ray. They point to the amount of pelvis bone that is covered by the leg bones on the x-ray. If you look at the pelvis, you can see that with the legs fully extended straight down, the legs overlay the very corners or tips of the pelvis. You can see the overlap through the leg bone. The picture above shows an even amount of overlap on both sides of the pelvis. The photo below shows a much larger overlap on the left of the screen than on the right of the screen. This is poor positioning.
The photo above is the same dog only a different x-ray than the first one. This second x-ray has poor positioning. Notice how much more the pelvic overlaps the leg bone (the green arrows) on the left than on the right. The result is the hip is pulled further out of the socket (the single red arrow) because of poor positioning.
The x-ray above is an example of poor positioning. Again this is the same dog as the good x-rays above. The dog is rotated. You can see the upper right hole through the body cavity is noticeably smaller on the right than the left. The pelvic wing under the leg is noticeably larger on the left than the right.
This photo graphically shows the results of poor positioning. This photo shows the same hip joint on the same dog x rayed on the same day. The hip in the red circle is a much deeper seated ball in the socket than the picture in the yellow box (which had poor positioning to produce this results).
Some people ask how the difference can be so dramatic. My feeling is that these are young dogs. They have loose ligaments (just like a young child). If I took some of the falls that my eleven year old does I would have numerous broken bones. It’s the same with our dogs. As they get older their ligaments are not as loose and they will probably not stretch as much. There may not be as much of a difference in older dogs. But at a young age positioning is critical.
The importance on positioning is often over looked by the vet that is shooting the films. There may be a number of reasons for this:
- It could be lack of experience doing hip x-rays.
- It could be a money issue with him. To shoot another x-ray because he made a mistake costs him money.
- It could be that by the time the x-ray is developed and he realizes the position wasn't that good, the animal is gone or awake from being knocked out.
In my opinion, none of these are good reasons. To get good x-rays you have to have a good vet. I have a couple of local vets that are very good with x-rays. If they make a mistake they re shoot it at their expense. We just recently started to see the OFA send x-rays back to the vets because of poor positioning. When this starts to happen on a consistent basis, we will start to see much better x-rays of the dogs.
Over the years I have seen some absolutely terrible jobs of x-raying dogs. As time goes by I will continue to add poor x-rays to this article so people can learn what to look for.
There are several operations that are being done today to correct a bad hip and allow the dog to live a normal life. The x-ray below is an example of what a hip can look like after the operation. This operation needs to be done at an early age.
This is a photo of a very bad set of hips. It's questionable if surgery could even correct this dog’s problem. These are hips from an 8-month old German Shepherd that came from a back yard breeder. A dog with hips like this should be put down. It is facing a life of pain.
The 2 x-rays above are of the same dog (a Border Collie). The top x-ray was taken at 8 months of age. The lower x-ray was taken at 4 years of age. This can give you an idea of what will happen to bad hips over time. Notice the thickening of the neck of the joint. The ball also shows signs of arthritis. This dog is living as a house dog where her exercise is monitored. When the pain gets bad she is given Rymadil and this seems to make her comfortable.
Same Dog 9 Months Apart
Here are photos of 2 different x-rays taken of the same dog taken 9 months apart. The first x-ray showed the dog having bad hips. If you look closely you will see the positioning is not correct. It's not that bad but it is also not perfect.
Taken Sept. 2002
The second photo below shows the dog with good hips. The positioning has been improved and this has made a big difference in how the x-rays look.
Taken June 2003
My advice to anyone would be to not accept incorrect positioning of any kind. Discuss this with the vet before the x-ray. Show him this article if he has any questions. I personally will not pay for a bad x-ray.
I recently had a similar situation with a young dog that I x rayed at 6 months. The picture did not look that good but the rest of the litter was good. So I redid the X-ray at 9 months and saw an entirely different x-ray. The dog will pass OFA if the x-ray stays the same.
I would also recommend swimming a dog to build muscle mass if there is any question on the hips. The better condition a dog is in the better chance of a good x-ray. I have a friend who has watched the OFA on a yearly basis. She has noticed that there are more bad hips in the winter months than summer months.
For me this translates into dogs not being in as good physical condition in the winter months as the summer. In the future I will not be x-raying dogs in the winter. I will also make sure that my dogs are in excellent condition when the x-rays are taken.
Poor Hip Positioning vs. Correct Hip Positioning
These x-rays are of the same dog taken with poor hip positioning on the left and correct hip positioning on that right taken just several days apart.
Poor Hip Positioning
|Good Hip Positioning
While this dog does not have perfect hips, if you look at the positioning of the x-ray on the left, the hip positioning makes the dog's hips look much worse than they really are. This was confirmed when the dog's owner took this article back to her vet and asked the vet to re-do the x-ray with correct positioning.
The Following are 3 x-rays of the same dog done
at different times.
January - 2003
Positioning still not correct - look
at right hip
May 2003 Better but not perfect. Look
at the right hip in all three shots.
This is the worst case of hip positioning
that I have ever seen. The Vet that took them and gave them to
the customer should get out of the business.
What you can do to prevent bad hips
With all this said - if you are reading
this article and are asking yourself what you can do to make sure
your dog has healthy hips? The SV in Germany (the German Shepherd
Dog Club of Germany) has proven that genetics is only responsible
for about 25% of the bad hips in dogs. This means that 70% to 75%
of the bad hips are caused by environmental issues.
There are things that help:
1- Keep your dog thin - when I say thin I mean you need to see
a definition between the ribs and loins of your dog. I cannot stress
this enough. The more weight a dog carries the more pressure on
the hips. This is extremely important when the dog is growing (between
8 weeks and 18 months)
2- Do not over exercise your young dog. DO NOT TAKE A PUPPY JOGGING
!!! Not until its older than one year of age. Over exercise is
the fastest way to destroy hips.
3- Feed a quality all-natural
you don’t want to
feed a raw diet at least feed it an all-natural commercial diet.
I have an article on the various commercial kibble - we also sell
one of the best called "Honest
Kitchen" We have fed this
for years and feel that it's the best we can find.
We stress the diet with our puppy customers and it has made a
4- If you have a question about subluxation in a young dog - SWIM
the dog!! Take the dog swimming every day for 3 or 4 months before
you have x-rays taken. Swimming is the best exercise you can do
for a dog. It is way better than jogging the dog. When you stop
and think that subluxation means the head of the femur is loose
in the socket - does it not make sense to exercise the dog so the
muscles and ligaments tighten up the dog as much as possible.
5- We give our dogs 99% Glucosamine supplements - we
also sell it to customers click here for details. The fact is I take the
same product myself (in orange juice)
The fact is you can do all of the things
mentioned above and still get bad hips. That’s the sad
thing. I have bred over 350 litters in 30 years, the dogs I breed
have good hips 6 to 10 generations
and we will occasionally get a bad hip. I will say that the percentage
of hip problems in our kennel is much much less than breeders who
do not follow this protocol.
THE WORST POSITIONED HIPS I HAVE SEEN
The x-rays above were sent to me in Feb. 2006.
They are the worst example of hip positioning I have ever seen.
The Vet that took these should give up his day job and seek another
The above 2 pictures are of awful
positioning. The hips are bad however, and no matter how they were
positioned it would not have made them look any better.
Read our Q&A on Hip Positioning.