Animal Fiction

Have you ever given your characters pets? I have pets on the brain today because of several research projects and the fact that I own so many myself but I began to think about books I've read, movies I've seen. Once in awhile there is a pet involved, usually if it somehow specifically relates to how a character acts such as in 'As Good As It Gets' or has a pivital role or leading role itself as in 'Homeward Bound' but do you ever give your characters a pet just to as a part of their background? I know one writer who did--Jenny (most known on here as I M Cupnjava) in one of her currently published works 'About to Sin'. Hers was a cat. I had a few horses in one of mine, barely mentioned and yet important in their part of the story. I've yet to have a central character that is an animal although I did have a demon (Alexander in Hell's Own) if that counts.