Musannaf Ibn Abi Shayba 19:441

Abu Bakr narrated to us, he said: Ma'n ibn 'Isa narrated to us, from Ibn Abi Dhi'b, from al-Zuhri, who said: If a man commits an act with an animal, the full prescribed punishment (hadd) shall be inflicted upon him. And whoever accuses a person of [committing an act with] an animal, the prescribed punishment (hadd) is upon him.