It's wrong for humans to harm animals for our benefit. We would be quite upset if the role was reversed. Animals are a species just a little below us. It's our responsibility to make sure they're safe and cared for.
Bishop Desmond Tutu said "But there are other issues of justice--not only for human beings but also for the world’s other sentient creatures. The matter of the abuse and cruelty we inflict on other animals has to fight for our attention in what sometimes seems an already overfull moral agenda. It is vital, however, that these instances of injustice not be overlooked." Our dominion over animals is not supposed to be despotism," said Bishop Tutu. "We are made in the image of God, yes, but God – in whose image we are made - is holy, loving, and just. We do not honor God by abusing other sentient creatures."