Going all tree-hugger on me, I see... an amusing twist of my words, but clearly not what I meant.
Think about it. If animals were self-aware, they would NOT be satisfied living the simple lives they live. They would do what humans did: adapt, evolve, and conquer! Create things! Build things! Dogs wouldn't be sleeping all day, or playing with chew toys, or licking themselves. Who can say what they would be doing? Perhaps things similar to what humans do, or maybe not. But they aren't doing anything that proves they are self-aware.
If you were a self-aware dog, suddenly thrust into this hierarchy of being, wouldn't you question it? And then, maybe even rebel against it?
Humans have dogs as pets, not the other way around. It is that way for a reason. Humans are self-aware, and dogs are not.