Resoman

As I type this, I'm recovering from a dog bite I received four days ago. I was riding down a country road that I'm very familiar with and was approached (silently) by a medium sized short haired dog who got on my right side and started barking and snarling. I tried to ride away, but she got in one good charge and put a good sized gash in my calf. A lot of blood, a lot of pain and a long ride back to my car.
My leg was sewn up at the ER, and the local Animal Control has located the dog and, hopefully, put it in quarantine by now.
Anyway, what are the best dog repellents these days? I had a pepper spray with me but didn't have enough warning to get it out of my handlebar pack. A neighbor recommended the deterrents that make sounds that somehow subdue dogs. Are they really effective, what's a good brand name? Is there anything else I should consider? I don't want this to happen again,
Gary,
Elgin, TX