I've only raised a gun at an aggressive dog one time, and it was 2 labs that ran up on me during turkey season several years back. I knew who's they were which probably helped them. they charged me to within about 15' then stood there snarling and barking. I had my shotgun pointed at them with finger on the trigger and made my mind up that if they took another step, they were getting a face full of lead. Thankfully they didn't and eventually ran off when I stood my ground.