Funny you should ask this question. I just received an email from a long-time friend and big-time bicycle tourist. He and I met about 15 years ago at a century ride he had organized in a small Wisconsin town. On that ride, I was about 40 or so miles into it, riding on one of those typical back roads, when a pack of gnarly dogs came out from behind the bushes. I stopped as there was no way to beat them. There were six of them, and they soon circled me, most of them wagging their tails, etc. Soon, their owner came out from behind the woods; he looked like he just got out of prison and/or a meth lab. He hollered at his dogs to come to him and get away from me. All but one obeyed. This one took a nip at my thigh. At the time, I only saw a little bit of holes in the spandex and no real blood. The owner asked if I wanted to go behind the bushes on to a trail that led to his home that was very invisible to my eyes. I politely declined and simply poured water from one of my bottles over my leg. I got to the ride's next rest stop about 10 minutes later and probably put more water on it. I did not think much more about it that much more on the ride. At the post-ride party at a local firehouse, the ride organizer wrote down my name on the back of a paper plate, and I took his email address and phone number on the back of a business card, as we hit it off right from the start. When I got home later that night, my wife and her sister suddenly noticed a major black and blue bruise all over my thigh with a bulls eye centered right where the dog bit me. Since the sister had some nursing background, she convinced me to go to the local hospital. I got a TB shot. I was asked if the dogs were vaccinated. I had no idea. The ER put a call out to the sheriff's office of the county where I was bit, and I was told to try to locate the owner of the dogs ASAP. When I got home, it was rather late, so I sent an email to the ride organizer explaining the situation. He and his wife called the next morning. They asked for the location where I was bit. I told him, "well, it was on some back road with a bunch of woody vegetation. There apparently was some home or mobile home behind the woods. There may have been a farm about a mile down the road, and oh yeah, I would guess the rest-stop at around 40-45 miles was about 3-5 miles away." To the surprise of them and myself, they were able to retrace my directions on bike and find the guy and his pack of dogs. The dogs apparently had killed one of the farmer's sheep once upon a time. All but one of the dogs had vaccines accounted for. This one dog was immediately quarantined. The ER and/or sheriff (poor memory) told me I had a couple of options. I could start taking rabies vaccinations immediately. I could wait and see how the dog responded in quarantine. I could have the dog put down and get the lab results sooner. I opted for Choice 2 even though it increased the risk of being too late for a recovery if I indeed had rabies. I asked the doctor to give me the odds of the dog being infected. I forgot the number, but it was so low that it was not worth the cost of harming the dog even if the owner was a menace to society.
Oh well, this was a long-winded story that did not answer your question. I of course never got infected with rabies. For about the next 7 or so years after this incident, I regularly carried Halt or pepper spray whenever I bicycled out in the country (I usually carried the stuff in my back jersey pocket, ready to be taken out in a moment's notice). I never needed to use it once. On those few occasions when gnarly mutts came out of nowhere, I began to learn how to do the cost-benefit calculations of whether I could outrun them. In the process, however, I have found that the very best remedy for any unleashed dog is to yell at it in as deep a voice as possible. Dogs are basically submissive creatures to humans unless irked otherwise. As I plan on at least two multi-week rides this year, I have no plans on bringing Halt or any pepper spray with me unless I opt for areas where grizzlies are present. However, if you are so concerned, I would bring Halt or pepper spray and keep a good bicycle pump nearby on the frame. I really would not be scared however. If you check this board or others like it, you will probably not find any story worse than the one I told.
Oh yeah, about that friend. The ride organizer sent me an email last night, saying hello. We have not seen each other in about 5 years. He and his wife have cut down on their touring from about 6,000 miles each year across the country and globe since their parents are now quite elderly and in need of lots of care. Perhaps I'll use one of my two-week vacations to bike to their neck of the woods and participate in their charity ride again.