
hiya,
You are right not to jump straight to castration as the answer, sometimes it is, sometimes it is not, as some dogs, without the testosterone, loose all their confidence, and a nervy aggressive dog is a far worse thing!
You could however try teh Tardac injection, thats just a chemical castration and lasts a few weeks, which might give you a clue as to whether castration would help or not.
Basically there is no easy answer, just socialise socialise socialise, an then do it some more.
Take him, adn a big pot of treats, to a bench in a park where u can see other dogs, but can stay a fair distance away from them.
If you have toys you can distract him with then thats great too.
Id definately have him on a headcollar and a flat or half check collar, with a double ended lead. When he creates over another dogs presence, ignore him completely, say nothing. When (and it may take some time) he ignores them, even if its for a split second, reward that.
The problem with shouting at your dog, is that he may easily think that you are shouting cos of the other dog. Similarly, physical punishment for his behaviour is more likely to be linked to the other dogs presence than to his reaction, so if he realises another dogs presence means he gets a smack/jerk on collar etc etc, he could double his efforts to make them go away.
There is another trick you can use, however it works MUCH better if you have a set up of non reactive dogs (adn i can appreciate not many ppl do)....i call it the run away trick...Secure your dog to a post (NOT with a headcollar OR choke chain, but with a flat collar and longish lead), have another dog walk past at whatever distance is his closest 'safe' distance (ie as near the dog can get when he will JUST react to it),,,,,, the second he reacts, say 'bad dog' and run off away from him. The second he is quiet, return.
Do that a few times, and then have the stooge dog sit still, rather than walk past, and work with that....if he is a smart dog, he should fairly quickly realise that his action means he does not get your support.
However, that method does depend on you having stooge dogs and friends available to handle them, dont try it on strange dogs in teh park, and if it upsets your dog too much, dont do it.
The other thing i would suggest is get your dog to be a bit more independant, set aside quiet times where he cant see you or follow you around.
Good luck,
Em