Didn't God say we were to rule over all animals?
Genesis 1:26 "And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth."
Rule, yes. Master, probably (cats say, "yeah, right. Just try it.") But I like to think of this dominion being a form of good stewardship because God has an affinity for shepherds, those who care for and defend animals.
It's best to be kind to critters because we're pretty much in the same boat:
Ecclesiastes 3:19
"For that which befalleth the sons of men befalleth beasts; even one thing befalleth them: as the one dieth, so dieth the other; yea, they have all one breath; so that a man hath no preeminence above a beast: for all is vanity."