A vicious dog must be tied short.
More French Proverbs:
He is a very bad manager of honey who leaves nothing to lick off his fingers.French
He looks for his ass and sits on its back.
French
He who bestirs himself sucks up, he who lies still dries up.
French
It is in vain to lean the ox to the water if he is not thirsty.
French
Loaning money causes loss of memory.
French
He who stops at every stone never gets to his journey's end.
French