Through reconditioning and subsequent corrections.
Here, (below) will be partial answer to your correction question.
For example the dog is aggressive to another dog. What happens to such a dog is that when he sees another dog his adrenaline shoots up in sight of another dog.
His master then gets worried that his dog will be aggressive when he sees another dog and his dog senses this worry of his master. That confirms to him that there is a reason to protect his master because the dog mistaknedly thinks that his master is afraid of the approaching dog. This will then spiral up into conditioning of aggression against a dog which is farther and farther away.
This conditioning spiral needs to be reversed through re-conditioning and then enforced. In another words we attack the problem from 2 sides.
1st. we use positive reinforcement. Your dog sees another dog and we (BEFORE OUR DOG TURNS AGGRESSIVE) use marker word YES and display happy go lucky behavior and talk to the dog with high pitched voice and play with the dog tug of war or give him a treat.Thus we condition dog stimulus: DOG = Reward of paly or food. ( play is better). At the same time we turn away from said incoming dog. This needs to be repeated many times sometimes usually 100X -300X ( 10 x per day for 30 days) before results are obvious and uour dog is happy when there is another dog in his site and wants to paly wirth us or expects treat . That way we are conditioning a dog to be happy rather then angry. We are also diffusing his over-protectiveness of us since we do not act afraid, but we act happy instead. This however still left the dog in charge which could be dangerous because such behavior of unwanted aggression will invariably rare its head in different scenario.
that leads me to point
2. Correction. Correction is a complex issue and what I am describing below is the only one way to do it.
Basically when and only when the dog is reconditioned and me and my dog find ourselves in the same scenario, me, my dog, strange dog and I see that the my dog is looking at the other dog and his brain wants to slip into aggression Yhen I say sharp NO, turn around and if my dog does not follow then he will get unavoidably a correction by my leash which I may or may not accentuate with my arms,..depending on a dog. If the dog follows me then we then slip into positive tug of war game or treat reward and I act like happy go lucky ass.
This will halp the dog to realize that i am in a leadership position and there is no need for him to protect me .
There were literally tens of dogs saved by this training from being PTS and their owners still thank me.
Prager Hans

so basically you are using desensitisation and counter conditioning, but rather than put in extra reinforcement time you take the aversive shortcut. Can work. Can also create an unexpected setback in that what you have achieved in teaching the dog that other dogs are nothing to fear you undo by giving the dog a jerk that creates discomfort/pain. Confusing for the dog in that you teach another dog = play and joy then do a u-turn which teaches the dog that another dog coming into view = pain/discomfort

Nice dog. Do not do Alpha roll. It is hard to do it properly and generally there is no need for it. Also your dog is too old for that.
However, I do not think that your dog can not roll. I think that when you making it to roll he thinks that he is in tremendous danger of getting hurt. It is an inherited instinct. It as "knee jerk" reaction and your dog can help itself to act like it. It is an inherited just like his color and thus there is not much which can be done to reverse it . And especially in this age and with such a strong response it is not necessary at all. Your dog when it lays on the side is in different mind set and does not feel the same response as it is if you roll it all the way on its back.
My advice : just do not do it. It is not necessary and will not do any good.
Prager Hans

So why breed &/or trade in cross breeds ??

I see what you mean.
however the dog reads that he needs to follow me or heel because I am in leadreship position. Thus here is the chain : Another dog-> Play =joy, but not folowing me the learder-> discomfort.
In other words we can condition many responseso into stimulus -> reward sequence. It is totally legitimate to do this
1.dog = positve
2.follow the handler (or sit or what ever) = positive
3. not follow the handler ( or sit or what ever)= negative
4. and if the dog finally follows the handler ( or sit or what ever) = positive again.
( FYI:I use heel and not sit because it is important for handling this situation)
In the other words I can demand 2 or 3 or 4 or more performances before the dog gets positive reward. That is as long as it is one chain of tasks "in presence". Like I can reward the dog after sit or I can deleate it and reward the dog after sit and down or after sit and down and stay and come and heel and then reward. And it is legitiamte to correct the dog for braking any of the comands which were in the "present " chain and then reward the dog after the last one is performed. That is, we can correct for braking it, only if the dog understands the command which was trained with positive only.
Prager Hans

I will assume that your question is sincere.
Mal-shep like Mia which I am sure is the dog which you are referring to since she is the only such dog which we have ever sold, is combination which mainly law enforcement require, if they need extreme dogs for S&R or detection and so on. These combination provides level headedness courage and size of GSD and extreme drive of Malinois.
GTSD is not and should be not extreme breed, but it should be a versatile breed. Thus I am against breeding some behavioral extremeness into GSDs. However I can see the need fr extreme prey drives in some situations and thus I/we sell such dog mainly to LE.
Mia is going to Police department in California.
Prager Hans

I havent got much time to be online just now and I appreciate your answers here. I just wanted to pick up on the one point in bold

although I agree with your points that a dog can learn to associate a tight lead with another coming - or the owner tensing up or whatever

I do not agree that agression is always to do with protecting the owner or resource guarding
a dog can very easily be agressive because they fear an attack from another dog

I also dislike people saying that an agressive dog is due to the handlers leadership
It is really depressing for everyone who lives with a reactive dog that the GP assume that your dog is agressive simply because you are not a good enough leader - there are many reasons for agression


I also disagree with you saying positive only is a dangerous way to correct agression
I have seen first hand that punishment is very dangerous

Mia and another dog in our area hated each other when they first met

Every day when they met the other owner gave Mia treats (she always has treats and gives them to all the dogs)
If either of the girls reacted I moved away and came back slowly
the other lady punished her dog and told her off for reacting

In a short time the other dog stoped reacting
It took Mia a little longer but we got to a point where both dogs could be walked together onlead with both of them seeming to be happy

so much so that the other owner decided her dog was ready to be offlead

one day another dog came up behind Mia , Mia barked at the other dog and the first dog charged in and attacked Mia - silently and very agressivly - Mia had punctures all up her back then on her chest where she was bitten when she was on her back, Mia also lost a tooth and was lame for a few days

The other girl had given the impression of being 'cured' when in reality she had only supressed her outward reaction and not the actual feelings

What makes you assume that it is the leadership position that the dog is reading? To me, the dog is reading that he needs to follow you or heel because if he doesn't, he will receive a jerk which equates to pain/discomfort.

Wouldn't the dog be showing more respect for the handler if s/he followed without the need physical pain/discomfort for not doing so?

I train heelwork off lead mostly. It isn`t hard.
Loose-lead walking I train by using the Drunken Walk method which encourages the dog to follow you rather than lead. In this, you simply weave every time the dog moves ahead so he trots back into place to follow you. No shouting or correcting needed.

Good looking dog! I would agree. Our Bangkaew mix was instinctively extremely territorial and aggressive and as a pup of about 10 months he thought it was expected of him to fearlessly protect us. It was only when he was trained that we did not want him to do that, that he accepted strangers coming in to the apartment. I must admit that I can not stop him being aggressive to another dog on his territory. So this guard dog can be aggressive but it can be controlled.