养虎遗患：遗：留下；患：祸患。留着老虎不除掉，就会成为后患养虎遗患
养痈遗患：留着毒疮不去医治，就会成为后患。比喻纵容包庇坏人养痈遗患
养痈成患：留着毒疮不去医治，就会成为后患。比喻纵容包庇坏人养痈成患
养虎伤身的意思
养虎伤身：饲养老虎，自伤其身。比喻纵敌留患。[bringing up a tiger one sustains injury himself——to be injured by one whom one has been kind to] 饲养老虎,伤及自身。比喻纵容坏人,害了自己兀术听了,大叫道:“罢了,罢了!此乃养虎伤身也!”—— 清. 钱彩《说岳全传》