I have grown up surrounded by many different animals from horses to snakes. I can say it has been my experience that although some species have larger processors (mental capacity) than others, they are all limited by their internal wiring (instincts) and software updates (training and life experiences).
I have personally trained horses, dogs, cats (as much as one can train a cat) and in some cases reptiles (again to the extent that an reptile could possibly be trained. I can say with certainty ever behavior I have witnessed can be directly tied to either an instinct or some sort of learned behavior. Original thought and or self expression is not something I have ever seen in any animals I have worked with.
As far as love, I personally believe love is nothing more of the action of putting others before oneself regardless of one's feelings for that person or thing. Emotions have nothing to do with it. With that said, some pack instincts could follow those lines and appear to be love however I think it (when animals are concerned) is a programmed response and not a conscious decision.