It has often been said of those who have plans to kill their dogs, they should begin by giving the canine bad names.
Giving the dog a bad name steels the nerves of the owner, now turned killer, before he snuffs life out of their pet.
It must also remove a sense of guilt in the killer. For the absence of guilt convinces the killer the dog is indeed bad. It offers legitimacy to the motive to remove the canine from the face of the earth.