Matthew 7:6
"You must never give the things that are sacred to dogs, and you must never throw your pearls before hogs, for fear they might trample them under their feet and turn and tear you to pieces.
Philippians 3:2
Look out for those dogs, those mischief-makers, those self-mutilators!
2 Peter 2:22
In them is verified the truth of the proverb, "A dog turns back to what he has vomited"; and of that other proverb, "A sow that has washed herself goes back to wallow in the mire."
Revelation 22:15
The dogs, that is, those who practice magic and immorality, murderers, idolaters, and those who love and practice lying, are on the outside.