Not Going Willingly
Going to the vet seems like a bigger issue for the owner than this dog. That’s a big dog to have to throw over your shoulder. It’s probably either this or dragging him across the floor with its leash which can’t be easy either.
That dog is almost as big as its owner, and he’s not going to make going to the vet easy on anyone else except for himself. All he has to do is transform into a fuzzy ball of dead weight that has to be carried in and out of the vet’s office in order to prove his point.