Our German Shepherd mix has her own rat. Kira (dog) and Ashhamsterly (rat) are best friends. I will definitely have to get a video of them. Ashhamsterly seems happier when she is out with us and Kira than when she is with her rat buddies.
I have 2 boxers and my boy is so hyper and would love a cat but I think that he would frieghten the poor thing even though he just wants to play. He also takes quite an interest in watching my 0.1 albino bp crawling around her terrarium. Its so funny. He just lays there and whines repeatedly.