cook the hound when the hares have been run down; trusted aides are eliminated when they have outlived their usefulness,as the hounds are killed for food once all the hares are bagged;
翻译
兔死狗烹
英语lit. to boil the hound once it caught the rabbit (idiom), fig. to get rid of sb once he has served his purpose
德语der Mohr hat seine Schuldigkeit getan (V, Sprichw)