The urine of one dog will not pollute the ocean.
More French Proverbs:
He asks advice in vain who will not follow it.French
It is in vain to lean the ox to the water if he is not thirsty.
French
Ready money works great cures.
French
When all you have is a hammer, everything looks like a nail.
French
Shear the sheep but don't flay them.
French
No day so long but has its evening.
French