What is the cause of hip dysplasia?
Canine hip dysplasia is an inherited disease. Its mode of inheritance is termed “polygenic” or “quantitative,” meaning that it is due to a combination of several genes, with each exerting its own effect and some more powerful than others. The exact number of involved genes is not yet, and may never be, known. Because of the polygenic inheritance, some normal dogs produce a certain percentage of dysplastic offspring. The sire, although physically normal himself, transmits to his offspring some of the dysplastic genes; the dam, although physically normal herself, transmits the complementary genes necessary to produce dysplasia in some of their offspring. The division of defective genes may be very uneven, with one parent contributing many more than the other. It is a well known and tested fact that polygenic characteristics are particularly susceptible to environmental influences. For this reason the severity of hip dysplasia in dogs can be manipulated by changes in pelvic muscle mass, g
