Run Quik, Run!

Many people who know about dogs, especially the larger breeds, know that they can be prone to joint problems, particularly hip dysplasia. Just what is dysplasia and how does it affect our 4-legged friends? Dysplasia actually refers to the abnormal growth or development of the part of the body affected. My poor dog, Verbal, has both hip and elbow dysplasia. In hips, there would be a bad "fit" of the ball and socket joint-the femoral head and acetabulum. Normal hips have smooth rotation of the femoral head in the acetabulum due to this proper fit along with the cartilage covering and lubricating fluid in the joint.

When an animal (yes, there are some breeds of cats who also get this) has hip dysplasia, the ball and socket do not fit well. The acetabulum is flattened and the femoral head is not held tightly in place, causing slippage and subsequent friction. This makes for an unstable joint and the body’s attempts to stabilize the joint only end up causing changes in the bones of the joint-this is arthritis, and can occur even in very young dogs. Verbal was noticeably "rabbit hopping" in her hind legs due to discomfort when she was only 6 weeks old! That rabbit hopping gait when a dog is running or going up stairs can often lead us to a diagnosis of hip dysplasia, but not always.

We know that some pets may show their discomfort due to hip dysplasia at a very young age as Verbal did, or may not have pain until severe arthritis changes occur in the joint as they age. Radiographs of the joint show us the changes that occur, but the degree of those changes don't necessarily correlate with the severity of lameness. Some very badly lame dogs may only have minor changes on the x-rays and some dogs with terrible x-rays may never show pain. It is true that lighter weight dogs do better than overweight or even normal weight dogs, and some dogs are just more stoic than others.

Genetics are a major cause of hip dysplasia, so ethical breeders always screen their breeding animals BEFORE they use them in their breeding programs. The OFA or Orthopedic Foundation for Animals has a huge data base of many heritable diseases of animals, and hips are a big part of this. Preliminary testing can be done at any age, but "official" OFA radiographs are taken and submitted for evaluation at 2 years of age. These must be done under sedation or anesthesia to ensure accurate positioning (and in affected cases, pain free positioning.) That is why our handsome patient, Quik, came to see us this morning. He is still too young for the official testing, but his owner found out Quik has a half sister affected by hip dysplasia. It is just smart to do all she can find out early if Quik might be affected as well-before too much degenerative joint disease occurs as a result. Some treatments can be done on younger animals that wouldn't be effective on older ones.

Quik is a bit shy but his owner has worked with him a lot. He is a very good boy, and did well for his exam and sedation. We positioned him for his hip radiographs by laying him on the table and extending his hind legs back and flat, parallel to the table-definitely not a position an awake dog would want to make willingly! You'll notice the hips are symmetrical and the patellas are on top of the femurs-good landmarks to tell us we have decent positioning for the radiologist to evaluate the joint conformation. Quik isn't showing any signs of pain or discomfort and when I palpated the joint there was no problem with the motion in either hip. This is truly a screening procedure today. We also took radiographs of his elbows while we were at it and the radiologist should get us his opinion in a day or so. I mentioned there are "treatments" available for hip dysplasia if we diagnose this condition. So far, Quik's hips look really good. In fact, his owner said he lifted his leg to pee just like the big boy he is for the first time this morning! Oh, the things we celebrate around here :) Young dogs with severe problems of conformation, such as when the ball is luxated or not in the hip socket can be treated surgically with a TPO or FHO-triple pelvic osteotomy and femoral head ostectomy. The TPO is a procedure where the pelvis itself is broken and re-plated in three places to re-position the socket over the femoral head. The FHO is considered a salvage procedure but I really like it and is what we did for Verbal. She actually didn't have a socket but more of a "plate"-that joint was really deformed-so re-positioning it wasn't an option. Instead, we removed the femoral head completely and therefore there was no longer any bone to bone contact-and no more pain. Her gait was fine after that, relying on the strong thigh muscles to support her limb-that is until she blew out her ACL in that same leg some years later! Very young dogs also may benefit from a juvenile pubic symphysiodesis, a procedure where the pubic symphysis (the cartilage seen connecting the right side of the pelvis to the left side) is fused early to allow for more normal alignment in puppies that may be predisposed to hip dysplasia.

Options for older dogs include total hip replacement surgery, where prosthetic joints are implanted, DAR arthroplasty where bone grafts actually build up the rim of the acetabulum to make a deeper socket for the femoral head to sit in. FHO's are still good options for older dog's, too.

Nutrition is a factor in "treating" as well as controlling degradation of the hip joint. Certainly we can't allow an affected dog to become too fat. Those large breed puppies who grow too fast or who have their bones and tendons grow at different rates put unnatural stresses on the bones, often causing dysplasia or other developmental problems to occur. 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. It is just common sense that feeding a Great Dane is different than feeding a Chihuahua! 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. Many people have utilized acupuncture and other alternative therapies for their pets.

While I tease Verbal about being my "genetic disaster," it is actually true, and a heartbreaking thing to have happened to her. We can only hope that all people who breed dogs will be as responsible as Quik's owner is, screening for this devastating, painful disease and weeding out the affected ones from the gene pool. That way our dogs can run and play through out their lives, happy and pain-free-run Quik, run!

Peace,
DrReneigh