'As I sat by her, feeling lonely and miserable, Jenkins came into the stable. I could not bear to look at him. He had killed my mother. There she lay, a little, gaunt, scarred creature, starved and worried to death by him. Her mouth was half open, her eyes were staring. She would never again look kindly at me, or curl up to me at night to keep me warm. Oh, how I hated her murderer! But I sat quietly, even when he went up and turned her over with his foot to see if she was really dead. I think he was a little sorry, for he turned scornfully toward me and said, "She was worth two of you; why didn't you go instead?"
Still I kept quiet till he walked up to me and kicked at me. My heart was nearly broken, and I could stand no more. I flew at him and gave him a savage bite on the ankle.
"Oho," he said, "so you are going to be a fighter, are you? I'll fix you for that." His face was red and furious. He seized me by the back of the neck and carried me out to the yard where a log lay on the ground. "Bill," he called to one of his children, "bring me the hatchet."' - Beautiful Joe: an autobiography of a dog, Saunders.
Sometimes humans apply their sense of justice inappropriately to a different kind of being. Humans are, of course, quite within their right to do violence to their own when their moral sense requires it, but I'm not as willing to give them blanket approval to do what they like to other kinds.