I once had a Chihuahua that had a pet cat. It was such a treat to see the two of them play, especially when the cat would run up a tree just to mess with her. 
@TheMom I once had a female calico that just decided to move in with me. Couldn't even get close to her without getting hissed and snarled at,and she would back it up with claws and fangs,if necessary. Lived in one of two houses on what had been a 30 acre horse ranch outside of Denver.
I would let the cat out when I went to work,and let her back end in the evening when she would scratch at the door.
Opened the door late one Saturday afternoon to let her in,and a fully-grown female Doberman followed her into the house,crawled up in a chair and went to sleep. No collar,no tags,and no other way to identify her. She had obviously had at least one litter of puppies,though.
So,I decided "Looks like the cat has a dog.",and went to the store and bought some dog food.
Best damn dog that ever lived. She has been dead since 1980,and it's a rare day I don't miss her.
That mean ass cat outlived her by 3 or 4 years. She was missing for a couple of days once,and when she did get back home,she had lost a front shoulder and leg fighting something big enough it bit through and crushed her shoulder. I could see the fang holes in her shoulder.
I knew she was back home because I heard the cat fight break out on the porch because it seems one of the other cats was in her swing.
Had to have her shoulder amputated. Changed her name from "Homicide" to "Tripod",and restricted her to the house after that.
My father hated cats all his life,but suddenly I could come home a little early and catch him cooking fish for her. He denied it,and still called her "that damn cat" and denied she ever slept with him when I wasn't there.
The last words he said to me the day he died was "Boy,you take good care of that damn cat!" He had finally met something more hardheaded than he was.
