Ahh ok i see , you can make matters worse if your not carefull and your dog will be picking up on your nervs , Is he normally a friendly dog where other dogs are concerned . If he is its amazing how tollerant they can be and wont be holding a grudge against all dog kind because of this one act . If on the other hand he isnt dog friendly then you will need to keep him on lead at all times to safeguard you and him from future confruntations , I have read about dogs behaviour on a lead and basicly while you have him on it he has lost his choice of running away if something scares him , and so often through no other choice the dog will resort to agresion other dogs also see the lead as a red rag so to speak . You need to get his trust in you again so starting at home make sure he is confident that you are boss and then when your out with him he will trust your judgement and be less likely to react in a bad way , I can highly recomend a book caled the dog listener by Jan Fennell it gives you an amazing insight to a dogs way of thinking from being in a pack ( your family ) and making sure he knows his place and is well behaved .
I think as for your walks with him its safe to say that you know your dog best and so if you have good controll of him and he comes no questions asked then give it a go let him off but find a quiet park and do it for a short period of time then put him back on the lead , dont panic at the sight of another dog he will become protective of you and may become wary of the approching dog , i think its not wise to assume all dogs off lead are friendly but most dog owners if they are sensible will not have thier dog loose if its not friendly anyway .
Hope this helps a bit
Andrea

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