Yes I know it's totally normal  :)

He's got a brilliant temperament though, and is well adjusted to people and dogs.  He's just got his Good Citizen Bronze, and most people comment on how friendly and well adjusted he is.  I won't comment on how easy it is to get him to walk past some kids playing football or cricket though!

He just still wants to play with everything/everyone.  He's mostly good about greeting people nicely, but still tends to steam in at 100mph with other dogs.  He has good respectful body language on approach (keeps low, ears back etc), but on arrival is too 'in your face' and pushy trying to get a game going and in typical GSD fashion tends to land a paw on the dogs shoulder.

Course he's reached the age where other dogs no longer give him the freedom they did as a puppy, so the problem is he's getting growled at by all and sundry and is not so great at taking no for an answer, so lots of dogs are now resorting to yelling go away (teeth, snaps and barks).  He's fairly good at yelling 'uncle' when needed, but has got himself a tiny nick out of one ear from a warning already.

Best approach would seem to be having a well adjusted adult we see regularly put him in his place a few times, except we don't have easy, regular access to one.  Friends either have puppies, adolescents or oldies.  Most of the dogs at training classes are also youngsters too of course.

Suggestions on handling this for the best before he meets a random hound with low tolerance, or something happens to damage his temperament?

Er, you'd be lucky if his temperament hasn't already been damaged by letting him charge up to strange dogs. :rolleyes:

Why don't you recall him and put the lead on, then approach the other dog and owner with him on the lead? They should also have their dog on the lead - if they do not, then do everything you can to avoid them.  IF and only IF the other owner says it's ok and that their dog is non-aggressive to other dogs, then let him say hello on lead.  This is standard dog-owner etiquette for starters, however in your situation it would let you reduce his charging up to the other dog and control his saying "hello".  If it gets too exhuberant for the other dog, just walk back a few steps and stop his fun.

If he is getting "growled at by all and sundry...teeth snaps and barks", you can be sure that he is getting a very good lesson in aggression and how to be aggressive.  I always tell puppy owners that in an ideal world, their puppies wouldn't even know that aggression exists.  The experts are still out on whether dogs learn by imitation, but I've seen several strange imitation occurrences happening (ie dog not being trained watching a dog being trained - when it is their turn, they immediately do the same behaviour without needing to learn it as the first dog did) - and I don't think it's far fetched to say that aggression could be learned as a response behaviour also.  Unless you would like your dog to be aggressive, keep him away from any dog which might show aggression - or at least approach them in a controlled way so that you can then remove him from the situation.  One day, especially now he is entering adolescence himself, he might just decide he doesn't like being told off like this, and he will rebel and show aggression back, and before you know it you'll have a fight on your hands.

"Best approach would seem to be having a well adjusted adult we see regularly put him in his place a few times" - er, no, this would be the worst possible approach.  I'm not an advocate of pups or young dogs being "put in their place" by older dogs, for the above reasons. 

I don't recall saying he was off lead, and I am doing what has been suggested to me by those I have thus far sought or been offered advice from.

I specifically *don't* walk him off lead much of the time, as there are usually many dogs in our local dog walking spots.  It would be crassly stupid to have him off lead in the one situation where he still switches his ears off and is least likely to respond.  He is walked free when I can be sure I am likely to see dogs approaching, or ballgames before he is at a distance where reacts rather than responds to me.  When we are somewhere a little quieter he is walked free.  I have been steadily building his focus and recall.  He's getting good, but I know his limits on recall presently.

The scenario is most commonly thus:

If the other owner is not happy or is clearly pulling their dog away, or says something then we continue - and he's pretty good at this and we click and treat at appropriate times.  I'm sorry, but I rather thought that went without saying.

We pass a dog, or are walking towards another dog on the path...

We allow them to greet, he gets boisterous, or lurches (in play), *usually* when the dogs are nearing touching distance, sometimes at a longer distance - in which case he is limited by the extent of his lead.  Sometimes he seems more deferential and sniffs nicely rather than full blown boisterousness.  I will manage him with the lead such that he does not have total freedom or is not able to fly in at full speed.  However his desire is often to do just that, but even that is improving.  He quickly tries to initiate a game, or gets lively after initial greeting, but where it seems to be getting too lively I withdraw, or we both do.

Some dogs will join in a game, some will just have a sniff, some will growl - til recently this was rare,  but just lately seems to be becoming more common - though not all the time by any means.

There have been several situations walking or most recently at training where he has been growled at by dogs that have happily played or greeted in the past.  In the last couple of weeks there have been incidents of a stronger correction from the other dog.  *In these cases neither I nor the other owner have seen it coming.*  In all but one case the dogs were at a safe distance and on lead - which was the time he was nipped.  It also seems that he is now being growled at much more commonly - hence my desire to seek advice and understand what has changed.

Rereading my original post I suspect I should have tried to be much clearer on situation and quantity and I rather gave the impression it's happening far more than it is.

I have been repeatedly advised not to tighten lead, or pull him in close (which is of course a little challenging when he wants to be at the end of the lead rushing in to greet), and to allow him to greet as many dogs as possible. 

I have been advised by several people that he is at an age of just learning he is not a baby any more, so will be corrected by other dogs and not to worry about it. 

Several trainers and books have recommended the use of a mature dog in precisely the manner I mentioned, as being much better at teaching dog etiquette than us.  I have tuned out all suggestions involving choke chains and giving him a good shouting etc.

I am only trying to understand how best to manage things and understand what has changed, whilst still ensuring he gets plenty of socialisation and opportunities to meet other dogs, and hence understand dog protocols whilst trying to ensure I dont damage his temperament or feel he must be kept away from all.  When I understand the signal or action I am missing then we can proceed.

I'm clearly not seeing the signals from the other dog soon enough as apparently the first indication is the growl.  Perhaps I should initiate separating them earlier, perhaps he is just too gregarious for some or too invasive of their space.  But whatever it is I'm not seeing it, understanding it, or sure how best to proceed.

sorry that i misunderstood your post,
in your circumstances then I would carry on the greeting as you have been, as soon as any funny business starts, pulling, lunging, paws on shoulders etc etc then just walk away from the dog in the opposite direction. He will soon learn that any funny business means no fun!! I still have to do this with mine at times, he is now a year old..... I don't know if it is right or wrong, but when I walk him on a headcollar/check chain I do snatch him back into place if thats not what I want him to be doing! probably wrong in some peoples eyes I know, but not everyone appreciates a big dobe lunging out to play/ investigate  as some people just want to get on with their walk in a hurry!!
If I know that a dog is not going to be nice then I do keep him on a short lead and if possible would cross the road/avoid that area all together.

Somone else may have some better advice, but i'm sure things will improve with age.... thats what I keep telling myself :rolleyes:

We can only post on here in response to what information you give us...

You said:

"he still tends to steam in at 100mph with other dogs.  He has good respectful body language on approach (keeps low, ears back etc), but on arrival is too 'in your face' and pushy trying to get a game going and in typical GSD fashion tends to land a paw on the dogs shoulder."

To me, it doesn't sound like you're describing a dog on lead here - otherwise how can he run at 100mph on lead?  How can he have a long-lasting sort of approach, so that you can note his body language during it?  Maybe you meant this to be on lead - but that's not how it reads, so you might not have explicitly said he's off lead, but the fact that both myself and Emz independently read your post as such (when we hadn't read each other's) does suggest that.

"If the other owner is not happy or is clearly pulling their dog away, or says something then we continue...I'm sorry, but I rather thought that went without saying."

No, nothing goes without saying.  There are dog owners out there who will do everything under the sun, so make no assumptions and just respond to what is said is the best approach on here!

Personally, I wouldn't be letting my dogs greet every dog they comes across on a narrow path (or on any path).  If another person with a dog on lead needs to pass by close to mine, I will stand between mine and the other dog and will try to act as a barrier - both to my playful dogs which want to greet, and from the potential of the other dog, which may not be friendly towards other dogs.  If I'm with a well trained, older dog, I might ask it to sit and then stand between it and the other dog, again.  However, I'd only do that if I had a strong sit stay and treats ready to reward the stay during the temptation of the other dog being so close.

At the same time, making sure that my dogs sees friendly dogs at training classes and get the chance to run off lead with dogs that belong to friends, which I know will be friendly.

So - I'd say that your first mistake is in allowing him to greet every dog he comes across - which it looks like you've been advised to do by others, from what you say.  I think that's mis-advice, and you should be very select about the dogs you allow him to greet and only let him greet the ones you know he will get an ok response from - say, the ones at training which have not been aggressive to him.

The other thing to say is that you seem to have assumed that this is, in some way, your dog's fault.  Have you thought that you have a young, early adolescent male dog and the testosterone is starting to flow, and other dogs will know this and are increasingly likely to view him as a rival or a threat, especially if they are prone to male-male aggression already?  You say this is happening more frequently recently - well, he is maturing as a male dog and is more likely to be seen as a threat by others.

At training, I would be very wary of the other dogs - try not to sit by those which he has had issues with, or to leave them in stays next to each other, for eg.  Protect your dog as far as is possible.  Don't allow him to greet these dogs - have a treat ready for a "watch" command if you see his eyes wandering towards them. 

Generally, you shouldn't tighten the lead at the approach of another dog if you can help it by using a watch command, distracting with a treat to keep his eyes on you, putting him in a sit stay while the dog passes, or just changing direction.  But if he rushes to the end of the lead to greet, it's not YOU tightening the lead, but HIM, and that is different. 

The lead tightening advice (not to), comes from a situation like this: A dog is aggressive.  The owner is tense about this.  Every time the owner sees a dog in the distance, s/he tightens the lead to keep more control on their own dog - often BEFORE their own dog has even seen the strange dog.  Their own dog then sees the strange dog and reacts aggressively to it.  Over time, a tight lead, every time preceding a strange dog, comes to signal to the dog "strange dog alert" and is associated with the aggressive state which follows.  By the end of this you can induce an aggressive state in the dog just by tightening the lead, without a strange dog anywhere around. It has become the command for "aggression", if you like.  In the same way as saying Sit before a dog sits will eventually teach it to sit.  However, you need to have an aggressive dog first for this to happen!  You can't just take a dog which isn't aggressive, tighten the lead and watch the aggression....

You see, this gets garbled and passed down to pet dog owners as - never tighten the lead.  Well - if your dog isn't aggressive (which yours isn't), the lead getting tightened is not going to be associated with aggression in his mind, because that's not what follows.  If you need to tighten the lead to get him out of a potential situation, then do it! 

"I have been advised by several people that he is at an age of just learning he is not a baby any more, so will be corrected by other dogs and not to worry about it."

Well, you go on to say that you've tuned out suggestions of choke chains and shouting etc, and I think this is one more you need to tune out.  Unfortunately it's a bit more wide spread, even amongst positive reinforcement trainers, than choke chains.  The thing is - like you say, we don't and can't fully read dog behaviour or communication.  Therefore, how do you know that they are only putting him in his place because he's not a baby anymore?  How do you know it's not because he's a male and they're a male?  Or because their dog just wasn't socialised very well and doesn't understand his play overtures?  How do you know your dog won't decide "enough's enough" one time and respond with the aggression he's witnessed several times? 

The answer is that we don't and can't know that.  So - don't risk it.  For what it's worth, all of mine have gone through a similar stage of wanting to jump on every dog they meet, and I've done as described here.  None of them have ever been "told off" for this behaviour by another dog.  They have all matured and grown out of this behaviour and are now excellently well mannered dogs with good dog communication skills.  So - if you're worried that he "needs" to be told off - don't be - mine weren't and grew out of this as they grew up.  I mean - how many 5 yr old dogs do you know that want to jump on and play with every dog they meet?  There might be some, but very very few.  They almost always grow out of it - some quicker than others. 

Apart from all the good advice already given, what you need to remember is that until your GSD is properly mature at approx 3 years old, he will either be too overly excitable and an unwelcome playmate for many other breeds of dogs, or become a target of aggression from other under 3's who are threatend by his pure size and playing their hyerachy games.

You are correct in wanting to find over 3's for him to socialise with, and I would work really hard on trying to find him a good calm role model to learn behaviour from, too many young dogs together is not a good idea, it doesn't take much to turn a dog dog-aggressive, or dog-shy.

Continue with on lead socialising, with this breed once passed 6 months it is the best way to walk him, I would always walk him on lead until he is calm and mature and very well trained with recall, he can have all the excerise he needs from finding a nice quiet area for ball play and retreiving work. GSD's are people dogs anyway, they prefer to play with their owner and are extremely loyal, it is good to build on that bond, for him to know you are not putting him in awkward or dangerous situations and enjoying his outdoor exercise with you as his main focal point.

When your GSD is over 3, maybe even before he will happily walk off lead with hopefully no problem from other dogs or towards other dogs, as long as he has not been damaged from incidents throughout his puppyhood and adolescents.  Be very careful with his socialising, GSD's are fantastic dogs, my brother has two who are so gentle, obediant and  faithful, I trust them implicitley, work hard with your training and you will have a wonderful dog. :-)

why are you leaving him off lead when there are other dogs around? I would automatically put him back on lead till you know that the other dogs will be ok with this ladish behaviour (which most probably won't be!) and only let him off also if you can reliably get him back to you straight away. If neither of these happen then he should be on the lead and taught a better recall first! also if you need to do off lead exercise with him take him to a place where there aren't going to be many dogs etc and just let him have his interaction with others on lead in a controlled manner.
This is ust my opinion, i'm sure othere people will have theirs.
I know it is hard with them at this stage as they are growing up but still only pups mentally, but for your pups sake you need to take the lead before something bad happens to him