i was going to go with an American Eskimo, and then I watched this wary eyed little guy trying to bite a hose in half because someone dared to wash him and went "that one"
too bad as a little psych change for Donnie he's weirdly uncomfortable around dogs, so he's going to be weird around Bucky. (cooking lessons are going to be fun!)
he does have a few differences from ordinary human, I'm imagining he still has fangs and hasn't processed that yet, and even his human ears are a bit pointed, but he's going fully werewolf doggy at night lol
Donnie: clinging to the back of the couch hissing