Actually, the data shows that "pit bulls" (most people can't identify a breed worth a hoot unless they are a serious dog person, and if it is a mix, they are really hard to ID) are UNDER represented in attacks on humans. However, they tend to be horrid with other dogs, and if you get in to that mess and try to break it up, you have a real poop sandwich.
I got one in the ear/temple with a PR24 about 30 years ago. I was running and always carried the PR; the dog was in the are on its way to me after crossing the street. The sound was like a softball thrown hard hitting a wall. Worked; it was dazed when it got up, and it went home. I've pepper sprayed other dogs; worked ok, but cross contamination of myself or my dogs is a real issue since you don't get a vote on what the wind is doing when you need to spray.
ALWAYS ALWAYS ALWAYS contact LE and make the report. Be the first to call. That record might save your bacon in the future. BTW, one of the reasons my dog walking gun is a revolver is that I anticipate the need to make a contact shot to avoid risk to my dog(s). Jam a pistol in to the rib cage to shoot while I adrenalized, and I would be concerned about pushing the barrel out of battery; not a concern with a revolver. Animals are tougher than people, and I would not rely on a .22 unless I had no choice. My fanny pack revolver is a 296 loaded with the Blazer 200 grain gold dot.
Know your state law. KNOW your state law. DO NOT rely on rumors, the rules in other states, or LE. This can be a fact specific issue, depending on your state, and the arcana of such legal stuff is not well known.