22 We need not mention the Saint's other words (echoing the sanctions and penalties decreed by the Roman Pontiffs) against those prelates who are negligent or remiss in purging the evil heresy out of their dioceses. It is fitting, however, to meditate on the conclusions he draws from these papal decrees. "Above everything else," he says, "the Bishop must be eternally on guard and continually vigilant in preventing the contagious disease of heresy from entering among his flock and removing even the faintest suspicion of it from the fold. If it should happen to enter (the Lord forbid!), he must use every means at his command to expel it immediately. Moreover, he must see to it that those infected or suspected be treated according to the pontifical canons and sanctions."
Source: Editae Saepe (Vatican.va)