 The hip dysplasia registry (public and private) collected by OFA through April 2015 also showed that there were 2,732 cats got hip dysplasia, and 2,708 (99.1%) were Maine Coons.Dysplasia was more severe in bilateral than unilateral cases and with increasing age.Polycystic kidney disease (PKD) is an inherited condition in cats that causes multiple cysts (pockets of fluid) to form in the kidneys.