rex,s have dainty little feet,with a thin fur covering,./.an overweight rex will place its weight accordingly on its rear feet-wearing down said fur-whereas a spot on the bottom of the foot will form,.depening on the seriousness of the over weight determines how deep this spot is-thus-creating sore/bloody hocks,..to keep the diet in check,- feed daily-70%fiber(timothy/orchard grass)-low fat-pellets 1oz.per#,anthing else is a treat,.as for toe nails if you cut them yourself,-with the proper trimmers,..know where to cut,-only trim off about a quarter inch,otherwise there will be bleeding,.sincerely james waller