It is a disease unfortunately very common in many dogs, especially in medium and large breeds. The hip dysplasia occurs at an early stage of osteoarthritis by more or less. The femoral head, fitted into the glenoid cavity of the basin is maintained by a fibrous capsule, the muscles of this area, and by a ligament called the "ligament of the head."
In the case of dysplasia, there is a failure of this ligament: It does not set more fully when the head moves abnormally in its cavity, resulting in deformation and osteoarthritis. Although it is hereditary, and despite the efforts of breeders, the transmission system very complex e dysplasia does not eradicate it completely.
It should be noted that other factors than genetic transmission may play in the development of this condition: The food and the environment, with any excess physical activity.
The symptoms are not obvious, apart from a suspicious approach in the puppy waddling heavily on the hindquarters, more than most of its congeners. In adults, there is a limp in the morning at sunrise or near a long time off. These symptoms vary greatly from person to person. A dysplastic dog may not develop osteoarthritis until years later, as she said so much earlier in another. Treatment may consist of either the administration of anti-inflammatory drugs as tablets or injections, or surgery. There are many techniques, according to the progression of the disease and the general condition of the dog. We also practice today prosthetics, but more expensive method that seems to be effective.
Depending on the severity of dysplasia, and after a diagnosis by X-ray (only from age 12 to 18 months depending on the breed), the dog is classified as a category corresponding to their condition. A to E (A being the sign of the absence of dysplasia and E the most pronounced).

Hip dysplasia