whats the protocol for encounters w/aggressive dogs?

Question
Becky,
When encountering other dogs on walks who are aggressive towards my 14 week old puppy, what should I do?  There is a german shepherd in our neighborhood who thinks he owns a 2 block square area and comes running out of his garage towards us, then growls at my puppy until we turn around and leave the area.  I was considering leaving a note on the mailbox to tell the owners of their dog's behavior, although I know that they are aware that their dog is unfenced and unleashed, because I've seen them out there with him.  I was also thinking of carrying pepper spray in case the dog should attack.  If I do carry pepper spray, do you think I should knock on the door to tell the family I just sprayed their dog or just get out of the area?  What's the protocol among other dog walkers/owners?
Thanks,
Amy

Answer
Hi Amy,
You need to get Cesar Milann's book The Dog Whisperer.  He is really good at dog "body language" and I am sure you will learn a lot from him.  I am probably not the best one to ask, since my dogs are fenced in and I don't actually walk them.  The German Shep is definelty showing territorial behaviour.  I think if it were me, I would stop and talk to the owners and tell them your concern. Advise them in a nice way, that you carry pepper spray "just in case".  That way, you won't have to answer later if their dog gets out of hand.  They should be responsible dog owners and if their dog is agressive to other dogs, then they should not let him roam free, in my opinion.  Good luck.

God Bless,
Becky