Animals aren't people, yeah, but they certainly aren't things. And while they aren't sentient as we are, they certainly have consciousness and emotions.
It's like people seem to think that because cats aren't as smart as we are, and can't use human-style language, that they're not worth anything. But it's quite the opposite: Because we're intelligent (or so they say), and because we can use language and technology and whatnot, that means we ought to protect those who cannot speak for themselves.
There's a certain level of responsibility we have as human beings towards animals; and if we don't fulfill those responsibilities, there ought to be consequences.