At the age and physical condition described, screwing around with lesser responses is probably not smart.

Caveats: I'm not in Florida and have no idea what the legal environment would be like. I'm a lawyer (not yours), and get paid to fight stupid stuff. I am a (civil) prosecutor with a lot of criminal experience and still do criminal stuff for my office to help out. Among my assignments is Sheriff's counsel, so I deal with dog problem law. I also research, write, teach and litigate use of force. I am also the guy who helps out or does the work when harsh things need to be done to anyone with whom we are in conflict. I don't even remotely GAF about the feelings or well-being of people who need corrective action - if they lose everything they have and have a miserable existence, they have no one to blame but themselves. (Go to youtube and see what Conan said was best in life.) However, we have dogs (all of whom have been 60-140 pounds, one of whom was truly violent and dangerous to strangers), I much prefer dogs to people, and generally value them higher overall. While I am not interested in harming dogs, I have had to. Never shot one, but did a PR24 spin technique to one that was IN THE AIR leaping toward me, and pepper sprayed a few. Pepper spray is NOT a sure thing at all; don't rely on it.

1) Make a complaint to LE every time there is anything you perceive as a risk. Every single time. Good detailed info. Make sure you make a record of making the complaint - each call, each officer contact, whatever it is. It helps with any possible enforcement action (I'll be doing some litigation of that nature at work this summer as I catch up on other work, and the CAD history and witness/complainant interviews are important. The owner is an irresponsible donkey, with a pack of 9 GSDs he allows to run loose, all of which have ... problems with strangers. All he needs to do is build a fence, but he is too much of a jerk to do so.) Make sure you include in the complaint the facts of your particular vulnerability.

2) Research Florida law and local ordinances. Quite often, the state law can have provisions that would force a resolution, but depending on where you are, such problems can be low priority.

3) Understand that the shooting will be a BFHD. Be prepared for negative feedback, and maybe bogus actions against you. Make sure you are comfortable deadly force as a reasonable response to potentially lethal force against you. Consider developing an attorney client relationship at a low level with a good lawyer. If the environment is such that a good lawyer can persuade cops and prosecutors to not be stupid, a local one is better. If you have to scorch earth, an out of towner is likely to be better because they don't care.

4) Breed generally does not matter - size and temperament does. Most of us can kick a nasty small dog for self-defense. Once you get to 50 pounds or so, it becomes more a problem; less weight for someone like you. A determined 75 pound dog will mess you up. Don't play stupid games in that case.

My wife had a problem with an irresponsible idiot's dog a few weeks ago at our other house. She was walking Ruby and a loose GSD came up and tried to start a fracas. My wife got stepped on, scratched, and maybe a modest bite (unknown which dog did what) as a consequence. The owner of the loose dog is responsible for all of that. The owner was such a buffoon that she was trying to call the dog off with treats instead of taking the urgent steps to impose physical control - to the extent that a neighbor had to stop mowing his law and intervene. I made sure LE was involved, and the cops there did a good job - photos of her injuries, etc. They had no problem at all when I said that had I been there, I would have shot the dog. Period. Warning shot? No. Hell no. Never. Not with a dog, not with a person. Even LE, stuck under the moronic Garner decision needs to give a warning only if feasible, and only with a fleeing felon. Personal defense requires no warning of which I am aware, and you won't have time for talking. If you can LOUDLY make commands to the dog and owner when it is farther away, good. However, warning shots are clownshoes, and almost never prudent. Period.

Am I unpleasant and mean sometimes? Yup, if others make that an appropriate response. Am I wrong? Nope. It is in fact unethical to be considerate of the well-being of ill-doers.

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NHI, 10-8.