Originally Posted by Dbrooke407
But most people don't believe in asking before petting a strange dog because he must not have any issues if he's in public.
Not sure if you're being sarcastic or not but this is a very important line and is very true. Depending on the public setting you're in...people will naturally assume your dog is safe. Only an idiot would bring their aggressive dog into a public setting where it might do something stupid. Depending on where you are, you are kind of endangering the public (even though they are touching your dog without permission) when you take your dog and try to train/desensitize him to his fears...and they are fears.
Buy him a vest, or something that screams that he's in training. Last thing you want to EVER say in public is that my dog doesn't like X. People will look at you very strange. There are a lot of places you can find vests that say "dog in training, do not pet" or something like that and then people generally think its for service work and don't touch. Just make sure you're not playing the dog off as a service dog in training.