The Development of Canine Hip Dysplasia
Canine hip dysplasia (CHD) is a developmental disease. A developmental disease is not present at birth but arises with age. The series of radiographs below illustrate how a loose hip gradually develops degenerative joint disease (DJD).
At six months, this dog's hips exhibit extreme laxity, but no DJD.
At 15 months, laxity is accompanied by the development of "mild" to "moderate" DJD: the femoral heads appear slightly "flattened", the femoral necks are beginning to thicken and the acetabular rims are in the early stages of remodeling.
At six years, DJD has progressed into a "severe" form, marked by extreme bony remodeling of the acetabular cups and the femoral head and necks.