Imo it is not your responsibility to know where they are from. However if you care about the welfare of the animal you wouldn't let it go somewhere that it could possibly get taken from the new owner and euthanasia. Sadly the law (from my understanding) does not differentiate between dwarf and normal. All they see is the species. However I don't see how the law could come back on you if you sell it and the new owner then breaks the law with it.