Self defense from a dog?

Recently, I was talking to an ex-army man. He used to be a dog-handler while he was serving in the army. His question was, is it okay to shoot a dog? He didn't want to lose his carry license, but at what point can you shoot a dog attacking? Actually, I had no idea. Do you have to wait until you've been attacked? Can you shoot the dog as he comes after you? Does anyone know what the law says about this?:question:

I would think if you felt as though your life or the lives of your family around you were in danger that discharging your firearm for self protection would be legit. When I go for walks with my family I usually carry and have almost drawn on two dogs that came running up behind us, luckily it was a dusk and the 120 lumen flashlight to their eyes turned them away! +1 for escalation of force.

Dogs are just like any other animals ... you can shoot them if you are justified in doing so. Don't worry, they cannot testify against you.

Do you have to wait for them to bite you? No. At what point can you shoot? I would not venture an answer on that..its too case by case dependent.