With out knowing what type of dog we're dealing with it is impossibile to give any advice. A Poodle or a Rottwiler or anything in between? With out any further info a call to your local animal controll explainng the situation would be a good first step. They may come and help you or at least point you in the right direction. Your safety must come first so do take any unnessary risks, if you don't feel safe don't do it. It is an unfortunate situation but he will just have to understand you at least tried.
BTW there are many knowledgeable dog owners on this site. Just because it's a fish forum doesn't mean that's all we do.