Excessive Force or Self defense?

[LuciferLynn]

This is a powder keg. As an animal lover, I hate to see an animal harmed. However, the dog was snapping and growling at people and ran at the officer. Should the officer have allowed himself o get bit, possibly mauled? I'm sure the officer didn't think the dog was running up to him to give "kisses". I wish, though, that he had used a bean bag gun instead of actual bullets. The dog still would have been hurt, but not badly and would have run off.