©1994 by Robert H. Hathaway, D.V.M.
929 Hawthorn Drive
Lafayette, CA 94549
This article has been accepted for publication in the following dog magazines:
- Poodle Variety
- Afghan Variety
- Sight Hound Variety
It will also be submitted to Dog World and other dog magazines.
My specialty was Equine Chiropractic, until one day, an owner was explaining...“My horse has difficulties going up hill, down hill and jumping.” What popped into my mind was...“My dog has difficulty going up steps, down steps and jumping into the car.”, the symptoms of hip dysplasia.
I don’t know how long veterinarians, including myself, have believed that hip dysplasia is caused by a genetic defect. Someone in the past noticed that one breed was more prone to hip dysplasia than others. S/He couldn’t find the cause, and assumed it was genetic. That assumption has been passed on to veterinary students, since that time, as veterinary knowledge.
I now know, genetics is not the cause. I will agree, some breeds are genetically predisposed to producing offspring that develop this problem. It appears that the longer legged dogs are more prone to develop hip dysplasia after birth. The larger breeds with a narrow pelvis are more prone to produce puppies with this problem at birth. Naturally, there are cases in almost every breed that are born with hip dysplasia, and there are cases in almost every breed that hip dysplasia develops after birth.
There are two causes of hip dysplasia during whelping. One is due to a difficult passage through the birth canal. The other is due to pulling the pups from the birth canal. When the pup passes through the birth canal, one shoulder is forced back, and one hip is forced back. This makes the puppy slightly narrower for the birth passage. The problem occurs when the birth canal is too narrow for the pup. This squeezes the hip that is rearward further back, causing the sacrum to dislocate (subluxate). This is also what can happen when the pup is pulled, especially during contractions. It doesn’t take much force to dislocate a puppy’s sacrum.
Accidents are the other causes of sacral dislocations. The most common accident occurs when a dog is running, and turns on a slippery surface (tile, linoleum, wet decks or wet grass). The dog’s rear end usually goes out from under them to the side, causing the sacrum to dislocate. The longer legged the dog, the more force there is to dislodge the sacrum due to leverage.
If you or I were to get on all fours and walk, as we brought our legs forward, our hips would swing forward. The spine would bend to the right as the left hip came forward, and to the left when the right hip came forward. Nature provided the sacrum to slip back and forth across the last lumbar in four-legged animals. This biomechanical adaptation, prevents the spine from bending right, and left as their hips are brought forward.
When the sacrum dislocates to the right or left, it locks, locking one hip in the forward position, and the other in the rearward position. The spinal nerves exiting the last lumbar, and entering the sacrum are pinched. This causes the following:
1. Pain. It hurts to jump. It hurts to go up hill/steps. It hurts to go down hill/steps.
2. Nerve impulse is diminished to the muscles that hold the ball (head of the femur) into the socket (acetabulum). This allows the ball to drop or rotate slightly out of position. Which in time, can cause detrimental remodeling of the joint.
3. Nerve impulse diminishes to other muscles in the rear end, causing locomotive, and tail control problems.
4. The myelin sheath which surrounds the pinched nerves, begins to atrophy due to the lack of nourishment. This we term “Myelatrophy”.
5. When the dog begins walking, after the sacral dislocation, the hip that is stuck rearward, causes problems further up the spine. When this hip is brought forward, the spine bends to the opposite side (as a person on all fours). This continual irritation to this disc causes pain, inflammation, and in time, calcification to occur. Continual bending of the spine will eventually rupture the disc, or cause it to disintegrate, calcify and fuse the two vertebrae together. Think of bending a wire back and forth repeatedly in the same spot. It will eventually break. This is why we see more ruptured discs in short legged dogs. Their spine bends many more times than a larger dog’s, covering the same distance.
“DO NOT ASSIST IN THE BIRTHING PROCESS, UNLESS ABSOLUTELY NECESSARY.”
“DO NOT PLAY WITH PETS ON A SLIPPERY SURFACE.”
“DO NOT PUT PETS IN CAGES WITH SLIPPERY FOOTING.”
“CONSIDER SLIP PROOFING YOUR PROPERTY.”
1. Replace linoleum with 18" rubberized tiles. They clean up just as easily.
2. Purchase rubberized deck paint from a sail boat supply store, for your outdoor decks.
There are other accidents that can dislocate a dog’s sacrum, but they are minor compared to the above. However, accidents do occur, and puppies will still be born with dislocations. The following are symptoms seen in dogs with a dislocated sacrum, which are correctable:
1. Hip Dysplasia (If the joint looks good on x-ray, it is fixable. The others can be helped, including dogs that have hip replacements.)
2. Sore back.
3. Difficulty handling steps or stairs.
4. Difficulty getting in, or out of the car.
5. Difficulty handling rear legs when moving.
6. Not lifting leg to urinate. (Adult intact males only)
7. Squatting unevenly while urinating.
8. Short stepping with one rear leg.
9. Bearing weight unevenly on rear legs.
10. Partial paralysis of one or both rear legs.
11. Drags toes on one or both rear paws.
12. Unable to back up without falling.
13. Prefers to sit on one side of rear end.
14. Tail slightly off center. (This is normal in some breeds.)
15. Tail does not wag, or stand up.
16. Breath has a foul odor. (Continual pain causes the continual secretion of adrenalin, causing food to putrefy in the intestines.)
17. Hyper or restless for no apparent reason.
18. Not acting to form in the absence of other evident problems.
A dog with this structural problem may exhibit one or a combination of any of the above symptoms. Two dogs with the exact same dislocation may show different symptoms.
My Veterinary Chiropractic specialty now includes, equine, canine, feline, two mules, and any other four-legged creature that may come into my future.
Original Doc: hip02.doc