Can animals feel sadness (emotion)?

Its wrong to apply the conception of emotion, in a human sense, to species that aren't human. Of course there is evidence that some species are impacted by things the way we are, but they are their own kind. Who's to say that another species of animal that we perceive as lower than us experiences emotions in a different way, to a higher degree than we do. Emotions could be experiences that any lifeform can have, but since we can only perceive what we know as emotion, that is all we can go on.

I believe that when we're looking at supposedly "stupid" animals, we should hold them in high regard. Our ability to have unique experiences is evidence in itself that there are species that can have experiences that we can't.