Several years ago our cat, George, went into a serious decline. He was older (17) and he stopped caring for himself getting all greasy and matted. A young cat appeared outside our door and, after ignoring her for as long as we could, we let Chloe into our homes (and life).
The two didn't get along at first--and never became close friends. But George must have found something to like about having a hot young female around. He started taking care of himself, started eating again, and became more active than he'd been in a year or more.
George isn't with us any more but I believe Chloe gave him two good years of life.
If you're interested, you can see pictures of (Angel) George on Kara's website:
www.karalennox.com. Click fun-stuff and then pets. You can also see pictures of Chloe and of Da Vinci (the bird).