We have three cats. Two are four years-old, and the third is not only 14, but he is also diabetic. My daughter would desperately like to add a dog to the mix. We are worried about how the dynamics would work with the old cat, the rambunctious younger ones and then a dog. Also, the cats are strictly indoor and haven't been exposed to outside (and its perils, like tics and the like). What do you think? Should we hold off until we don't have the older cat? What sort of dog would tend to work best? Puppy, older dog, big dog, little one... Any and all advice appreciated!