Could it be that all animals have empathy, but some have a much smaller and/or different set of feelings they experience? As an analogy, if I see you eating candy, I can understand that you're currently tasting sweet, but if a cat sees you, it has no concept of sweet, because its tongue doesn't have those receptors. You can also see this in people, the most egregious example being "Let them eat cake" oft mis-attributed to Marie Antoinette. If you have never felt something yourself, either due to your upbringing or because your species has no capacity to experience that feel, is it that you have no empathy towards someone having that experience or that you simply cannot so much as conceive of the feeling in question?