We may not stable an animal in the inns of idol worshippers, since they are suspect in regard to bestiality. Anyone who leaves an animal at their disposal would violate "do not put a stumbling block in front of a blind man."
However, following this logic, we should allow placing female animals with female idolaters? No! This was prohibited, because idol worshippers commonly consort with their fellows' wives, and sometimes an idol worshipper visiting his paramour will not find her at home, but may find a Jew's animal there, and sodomize it, since they preferred Israelite's animals to their own wives. This made sense, since his own animal might become sterile, and with someone's wife, he might be discovered; thus, the Jewish animal was the most defenseless creature.
Art: The Young Shepherdess by Julien Dupre