Animals are definitely alive and feel just like us. The may be less aware of things around them, but we are not aware of most things either, like radio waves traveling around, but it does not make us any less alive.
I often wonder what would happen if you cloned a person. The clone would be alive by any measure. The big question is if that clone would know it is alive too. There is some new research that says consciousness, or how we know we are alive, is a property of matter itself. All matter, if connected the right way and having a dense enough amount of information, like our brain, would come alive. It is as if the entire universe is all alive and just wakes up more when connected the right way. Using this concept, even a stone rock could come alive given the right conditions.