Hereditary aspects of hip dysplasia in german shepherd dogs

Abstract

The inheritance of hip dysplasia was investigated in 64 litters comprising 405 German Shepherd Dogs in Sweden. The mode of inheritance was in accordance with that of an autosomal dominant trait caused by a gene with incomplete penetrance (about 60%) and of varying expressivity, occurring unilaterally or bilaterally and with varying severity. A recessive inheritance with incomplete penetrance could, however, not be excluded with certainty. The incomplete penetrance may cause a phenotypically normal dog to transmit the gene for hip dysplasia and produce offspring with hip dysplasia. A normal dog with many defective siblings and 1 or 2 defective parents is especially suspected of being a transmitter of dysplasia. To increase the probability of normal offspring, the selection of stud dogs with normal ancestors is important. When the parents and grandparents were normal; the offspring were always normal in this study. German Shepherd Dogs with dysplasia should never be used for breeding, since they are working dogs that need normal hip joints to perform their duties satisfactorily. In spite of selecting for normal hip joints, high quality appearance with the desired male or female characteristics can be maintained.