A powerful and incensed AI could destroy the foundations of global society before we would even know what's going on.
A powerful and incensed President could order a nuclear strike that could end civilization as we know it. Why the concern over a theoretical intelligence that could theoretically have emotion and theoretically have so much power it could theoretically do the same?
It doesn't matter what we define as a soul, it is the relationship humanity will have with artificial intelligences that matters. If we don't ask these questions, our children will wish we had...if they're still around.
http://www.nybooks.com/articles/2015/10/08/amazing-inner-liv...
We can't know whether animals have a soul any more conclusively than we can know that about ourselves. But it's arguable that one is not less probable than the other.