Hip & Elbow Displasia
What is Hip and Elbow Displaysia?
First the term dysplasia must be defined - it simply means the improper development of the structure referred to.
HIP DYSPLASIA
Hip dysplasia occurs in human beings and in dogs; the effect of the condition is to produce in varying degree a shallower cup or socket to the hip joint, and a coincidental flattening of the head of the femur or thigh bone. Even mild conditions result in arthritic and degenerative change, which will develop with time.
Hip Dysplasia is probably one of the most common of all inherited diseases that afflict the dog. Large and medium-size breeds are more seriously affected than small breeds. A great deal of research has gone into HD in an effort to discover the cause and mode of inheritance. It is now established that it is polygenically controlled. This means there is no single, isolated gene that can be held responsible, but that it is controlled by a number of genes within a cell. Because many genes are involved, the degree of inheritance varies, producing a wide variation in the severity of hip dysplasia. Litter brothers and sisters can often display a range of dysplasia, from severe to none at all, depending on the genes the individual has inherited.
The sad fact is, many breeders still refuse to accept the hereditary nature of Hip Dysplasia. They readily accept that width of scull, angle of shoulder, strength of bone and so forth are all skeletal parts inherited from parents and grandparents; yet refuse to accept that the structure of the hip joint must also be inherited.
Most hereditary conditions are affected by environment, so is the severity of this condition. Contributing factors involved are, rapid growth; overfeeding; nutritional abnormalities, and the amount of exercise given during early development. Overfed, overweight puppies are at greater risk of increasing the severity of any inherited predisposition to dysplasia. While good judgment is still required when feeding and rearing physically and mentally sound dogs; we must recognise that a structurally and genetically sound hip will likely stay structurally sound.
It is important to realise that dysplasia is not a "black and white" condition. The fact is that a high proportion of apparently normal parents will produce offspring with dysplasia, and that pups born to an affected parent may be clinically normal on examination. Mild or moderate HD is difficult to diagnose without X-Rays. It results in little or no pain until the dog reaches middle age when arthritis sets in. There is no doubt that with careful and selective breeding and routine hip testing of all breeding stock by X-Ray, this disease could be virtually eliminated or at the very least controlled.
ELBOW DYSPLASIA
Once again, the term dysplasia means improper development; in this case it is the elbow. There are a number of conditions affecting the elbow, all of which come under the term dysplasia.
The first sign of the condition is intermittent lameness, usually seen in Rottweilers aged 4 to 6 months. It can affect one or both elbows. Research into Elbow dysplasia suggests the condition is inherited and like Hip dysplasia is polygenic, possibly involving 3 genes. However, it does not follow that a dog diagnosed with Hip dysplasia will also have Elbow dysplasia or the reverse. There does not appear to be evidence that Hip dysplasia and Elbow dysplasia are related except that they both occur in rapidly growing breeds with an inherited predisposition for either condition.
In Australia the ANKC has introduced mandatory Hip and Elbow X-Rays for all Rottweilers used for breeding. Both parents of a litter have to be X-Rayed for Hips and Elbows before the litter will be registered.