Cows suffer so that humans can eat them and live. Those dogs suffered so that Michael Vick could swagger around like a thug.
To return to Moby Dick (hardly a book about animals' rights, but certainly one written by a brilliant and honest observer of the way things are, rather than the way things ought to be), as Starbuck (yes, I think they were named after him), the admirable First Mate, sits in the ship dining on whale steak (it's his due, since he's the one who killed the whale), he can hear, seperated from him by merely the planks of the ship's hull, the sharks feeding, in a frenzy, on the same whale's carcass. The similarity between the behavior of the men and the sharks is not lost on Melville or the reader.
Melville also observes--as you may remember--that the same men who hunt down and slaughter the whales, stroke and caress the heads of the baby whales who come to them for friendship in the open ocean; that the men observe the mother whales nursing their babies just as the same men prepare to hunt and kill the adult whales; and that the whales are slaughtered for their oil so that there will be lamplight in the churches back in New England, where love, kindness, peace, and compassion are preached. This is not an admonition, merely an observation.