I have 5 dogs: A 10 year old female poodle, a 9 year old male poodle, a 1 year old female yorkie, a 10 month old female yorkie and my 6 month old female biewer. It has worked out really well as my senior poodle girl is slowing down a bit, but my male poodle needed playmates to chase after him. They make a nicely balanced group. We have 3 siamese indoor cats and and a 15 year old tomcat who lives outside and sleeps in his heated house at night, and oh yeah the big fish tank. Now that I think about it we have a small petting zoo of animals. What was I thinking?