Has this happened to anyone else? Cow/llama saying I don't "own" them to trade/care for.

Update: in order to remove them, I had put a sim I didn't care about (not in world) onto a lot, add sheds, add the animals there (the sim household) and then go into main world and evict sim as well as deleting the lot. That combination removed them from my household inventory and they haven't come back!