When I was young, I was taught that the way "we" distinguished humans from animals was that humans used tools, and animals did not. It wasn't long after I saw pictures of chimpanzees using sticks to pull insects from decaying trees. "Tools!" gushed National Geographic, "Now we would have to re-think everything!" Today, of course, we know that there are a dozen or so species that use tools, including lowly crows and octopuses.
We used to think a lot of things about animals that weren't true — usually things that would diminish their existence from our own. We now know that many species have excellent memories, strong family bonds, feel a sense of loss, and possess many other attributes that we once held as a part solely of our own human existence.
But do animals love? I'm talking about love here, not mere attachment, as there is little doubt that is a part of an animal's experience. Now, there is a lot we don't know about the emotions of cats and dogs, and without delving too deeply into the nature of love, John Bradshaw, a researcher at the University of Bristol contends that dogs do "love" their owners. He suggests that cats admire us, and show the same kind of behaviours they show other cats that they like, but like the person you dumped in college, "they just don't get us." This is probably because cats have only been living with us for about 10,000 years, and most of their breeding has been to produce colour and style. This is opposed to dogs, who settled down with us 30,000 years ago and have been selectively bred ever since to get along with us better. Had that date in college been selectively bred to get along with you better, maybe he or she would still be around.
In the end, I wonder if it matters. It feels like they love us. We certainly love them. And love, like beauty, is in the eye of the beholder, no?