Most jurisdictions allow for shooting an animal that presents a danger. The burden of proof is generally lower than it is for self-defense cases involving humans.
I love my dogs. They're my friends and companions, and I actually do believe they have souls. That said, the law sees animals as property, and as such, they do not have the same legal protections people do.
That does not make wanton cruelty acceptable or legal, though.
In the depth of winter I finally learned that there was in me an invincible summer.