Hilchos Issurei Mizbeiach 3:15

Animals for any offering may be purchased from non-Jews; we don’t suspect that an animal might have had relations with a human, been the object of relations with a human, been designated for idolatry or been worshiped unless such a disqualification is known. This is seen in I Samuel 15:15: “They brought them from the Amalekites, because the people had mercy on the select sheep and cattle, in order to sacrifice them to Hashem your God.”

Hilchos Issurei Mizbeiach 4:1

An animal or bird that a human had relations with, that killed a human, that was designated for idolatry or that was worshiped is unfit to be brought on the altar.