This crime indicates sadism. People like this often move between offenses against animals, and those against humans. Rather than ‘killing the enemy’, they commit war crimes and rouse up long term resentment.
“This crime indicates sadism.”
I was not aware that it is a crime to put down a dog.
As for your diagnosis, yes, it could be the psycho-sexual disorder of sadism. Or it could be something else.
I wonder if you are a veteran.