Hey there! Just read your post and cringed. I was riding the greenbelt and had a man in a tree freak me out pretty bad. I found some mace at a running site called. It has an elastic band that is supposed to velcro around your wrist while you jog. I just stretched it around my handlebars and viola'. I have taken it out two times now when I was approaching men who creeped me out! I think it would also be helpful for crotchety old dogs.
It is just like anything else with women, we need to think ahead! Hope this helps!