What we think is not important. What is important is your locale, attitudes of local LEO, prosecutor and judge.
I have killed dogs for reasons I felt were justified. I try to follow the old, wise, adage of: shoot, shovel, shut up.
BTW, I can't count the number of squirrels, raccoons, possums
and armadillos I have killed because they tear up my wife's bird feeders, garden and lawn. Even a few skunks.