I have a question that I haven't been able to find an answer to anywhere else yet. I have a 10 month old male, intact, GSD. He is very friendly and has no problem around large crowds of adults - to which I spent countless hours socializing him as a puppy, and still do so today. I don't have any children, but made it a point to take him places where there were children so that he would get used to them. I never let adults pet him, but would let children pet him simply because if I didn't let "strange" kids pet him, he would never interact with children. Up until about 2 months ago he was great with children - he would gladly roll over and let a group of kids pet him. In the last 2 months though, his demeanor has changed. He is extremely uncomfortable if a child tries to pet him and at this point I've stopped all contact with children because I'm not sure he wouldn't bite them. A few days ago a little girl stood about 15 feet from him just watching him, and Ruger (who was on a leash) jumped up and barked at her. It wasn't an aggressive bark, but it wasn't his high pitched "I want to play" bark either. He is a very hard dog, and I correct him rather harshly every time he exhibits this kind of behavior, but it doesn't seem to be working. He has never had a bad experience with children teasing him or hurting him in any way - I have always closely watched the children whenever I've let them pet him, and make sure they know the correct way to pet a dog. To me, it seems as though children just confuse him and make him uncomfortable - they are right at his eye level and are often times nervous themselves around him, which I'm sure makes the dog even more weary of them. Does anyone have any advice as to what I should do? My next course of action was going to be to take a bag of treats with me wherever I go, and just have kids toss him treats, without petting him at first, and then go from there. But I don't want to do that if that will only make the situation worse. I am not an inexperienced dog trainer, but I've never encountered this problem before (with dog aggression only at children) and I don't want to make it any worse. Any suggestions would be greatly appreciated!

For me, I wouldnt bother trying to have him interact with the kids. It could just be one of those stages they go through, but I would rather just keep him at a distance and let him settle in and figure out their not toys and their no threat.

Though hard to say what's going on without seeing first hand, I'd agree with Steve. Could be a phase. Could be taking a dislike (for whatever reason). Could be something other. Either way, doesn't know how to bahave with kids, then no interactions with kids.
So long as he's not outright hostile to kids (safety first), work on neutrallizing him. When you're around kids (or any other distractions for that matter) work on engagement and interaction with you. Go to the Streaming Videos page; I'm sure there's a Michael Ellis clip discussing/demonstrating engagement. Use food. Toy may over-stimulate.
Let us know how it goes.

Thanks for the advice! I've set up a "training" date with a good friend of mine's 10 year old. They have rottweilers so I know the 10 year old isn't scared of dogs and knows the proper way to approach. My plan is to just have the 10 year old in the dog's presence and then do Ruger's daily obedience training as usual, until he is completely desensitized to the child (obviously might take more than one session). Any advice on what to do with those pesky children that don't know how to approach a dog? Is my idea of having kids that I encounter on my walks toss the dog some treats a bad idea? I'd rather him see children as treat dispensers than something to be uncomfortable around...

Treat dispensers are going to be what he focuses on instead of you. I'd rather have him as indifferent and disinterested in kids as possible.

Roslyn, mine is also not receptive to children, and does not like to be touched by them.

That being said, she is very neutral to kids as long as there is no prolonged direct eye contact (especially with kids who are at the same eye level as her)being made. I have done a fair amount of obedience and play training with her in the presence of kids, and that did help alot as far as her being neutral to them. I do not allow any child to approach her, ever.

Re the treats, I can tell you in my dog's case, she'd be ecstatic to accept treats tossed to her by a child, but it would not change her perception of kids.

"Any advice on what to do with those pesky children that don't know how to approach a dog?"

I have said, "I'm sorry, He's still in training and isn't allowed to play." I've also told people that he doesn't like strangers...ect. But on the few occasions where they run up quickly and I don't have time to be polite, I will sternly say "stop!" or "NO" and then try to be polite after the child has stopped in their tracks. A parent got mad at me for this, but the safety of the child and then comfort of the dog have to come first.

I also think that very young children make a lot of dogs nervous because they are not coordinated and their movements are irratic.

If a parent gets mad because you have told their child "NO" for engaging in a dangerous activity - running up to a large, strange dog - then shame on them and who cares what they think?

It is your responsibility to keep others safe from your dog, and for you to train your dog to ignore unpredictable things in the environment.

ETA: those are probably the same unruly children that would jump on your couch if they came to visit. Some kids aren’t trained (by their parents) to ask politely for things.

How timely... This link just came in this weeks newsletter. http://leerburg.com/playem.htm?name=flv/fear-period.flv&utm_source=nlist&utm_medium=email&utm_campaign=08022010

Wow! Thank you so much for posting that link. I think that's exactly what my dog is going through with kids. Thanks so much for the help everyone!