The sages of the Mishnah ruled that a Jew is forbidden to board his animal in a gentile’s animal boarding facility, because gentiles customarily have intercourse with animals (even dogs), and since according to the Torah even gentiles are forbidden to have sexual relations with animals (one of the Noahide commandments), one is forbidden to lead them into sin.
The Talmudic sages discussed this topic at length, arguing: if gentiles customarily have sexual relations with animals, why is one permitted to buy an animal from a gentile and bring it as a sacrifice in the Holy Temple? An animal which has been bred is not permitted as a sacrifice upon the altar. They answered this question: gentiles are careful not to have relations with their own animals; the female so they do not make her unable to bear offspring and the male so he does not wither away. But an animal which belongs to a Jew — it would not matter if they caused a Jew’s animal to become infertile or to wither away, so the gentile would have sexual relations with a Jew’s animal. The sages continued and asked: If so (if gentiles do not have sexual relations with their own animals because these relations cause damage to the animals, and therefore one may buy their animals for sacrificial purposes), why is one allowed to buy animals from gentile women for sacrificial purposes? The gentile woman is suspect of using the ox, the ram, and the billy goat for sexual purposes (for in this instance there would be no damage to the animal). They answered that even the gentile woman refrains from using her own animals for sexual purposes lest the animal, having enjoyed the sexual contact, pursue the woman and so make it generally known that she has had sexual contact with the animal. Due to shame she refrains from using her animals so. But if it were an animal belonging to a Jew this fear would not exist, for the Jew leaves his animal in her care for only a short while and then takes it back, so the animal would not have the time to pursue the gentile woman. If it is the case that a male will pursue a woman with whom he has had sexual relations, the sages asked why we warn Jewish widows not to stay in houses with male dogs for fear she will make sexual use of the dog. The dog would pursue her and everyone would know how she had used it, and for fear of shame she would refrain and not have sexual contact with a dog. They answered that a dog is different, for the dog’s attention to a woman could also be interpreted to be a plea for food and not necessarily for sexual contact. Therefore no woman fears that she would be suspected of having sexual relations with a dog.
The sages went on to ask: Why is one forbidden to hand over a female animal to a gentile woman? When a female has charge of a female there is no suspicion of sexual contact. They answered that we fear a gentile male will visit his gentile female lover to have sexual relations with her, and if he does not find her, he will use the female animal. Even if the gentile female lover is present, sometimes the gentile male will prefer a female animal owned by a Jew over his own gentile female lover. The sages said “They prefer the animals of Jews over their own women.” The sages also asked: what is the rule for birds? Do gentiles also customarily have sexual relations with birds? If so, it would also be forbidden to board birds at a gentile’s boarding facility. The sages answered that they do indeed also have sexual relations with birds, and related an incident which once occurred: A gentile bought a goose in the marketplace, had sexual relations with it, and then choked the bird, killed it, roasted it, and ate it. They also related an incident of an Arab who bought an animal thigh, cut a hole in it the appropriate size for his sexual organ, penetrated it, and then roasted and ate it.
(Babylonian Talmud, Tractate Avodah Zarah 22b)