The animals have a right to live. Every living creature is born by the grace of God. Therefore we should not interrupt their lives. Let them live and be happy. Animals are not of the same spiritual basis as the spirits that inhabit human beings.
Animals have no souls.
The souls are the same, but they have a different relationship with God. However, that does not mean you can kill them. Suppose your wife's children are born deaf, dumb and blind. You will love those children regardless. Everything has come out of God, and as such, you have no business infringing or encroaching upon another's life.