And no, I don't mean bestiality!
I mean me being your friendly, mostly obedient yet somewhat stubborn puppy, who will love you and give you dog-kisses and do most anything to please you, so long as you pet him, and tell him he is a good boy. I want to be treated like a dog, and be submissive, but not abused.
The setting can be from simple to more detailed, and can involve as many elements as seem appropriate. As a human being a pup, I like at least a collar and leash, a tail, and a few puppy toys...cages and muzzles and full-out pup suits/masks are fun, too, my favorite things, surely, but not required.