What? No, just no Aaron, get outta here with that garbage.
Of course there is intelligent life on earth besides humans, but we're talkin about the search for advanced intelligence (similair to humans) in terms of technology, etc etc, not just you tell Fido to go get his ball and he brings it to master.
Alien has nothing to do with intelligence.. so your theory of a dog or dolphin being "alien" is absurd.
It's perfectly clear that in the discussion you've entered, by "alien" they mean "not from this world", simply put.a·li·en ( P ) Pronunciation Key (l-n, lyn)
adj.
Belonging to, characteristic of, or constituting another and very different place, society, or person; strange.
Your last paragraph makes little sense and completely negates facts. The fact that there are more solar systems in the universe than there are grains of sand on every single beach in every single ocean on earth - and the chances that our solar system is THE ONLY one that harbors intelligent life is just not feasible. It has little to do with society getting bored... it's more about the more technology advances, the more we learn about the universe, and the more we realize how infinite it is - the more it raises the question - Are we alone?