Hi and welcome to the forum the OP did say how often she walks him, one long walk in the morning and once a night, so he's probably getting enough exercise. Of course she did mention he is onlead. As an owner who also must keep her dog onlead, it can be tricky to tire them out but I find mental puzzles and training help with this.

I suspect you are perhaps a Cesar Milan fan? I see no reason why this lady, who clearly loves her dig greatly should need to give it up until she has tried to solve the situation, she clearly cares and is willing to work at it. I'm sorry but I disagree with your dominance theory and feel it's a but outdated. This dog was attacked the displayed fear, nothing to suggest that he us being dominant. GSDs can be insecure and I agree to benefit from a firm but fair leader, without this leadership they may feel the need to step up as protector. However this dog needs time, understanding and gentle controlled exposure to the things it fears, not dominating which could make things worse. However I agree it also needs set boundaries and once he feels looked after and protected by his owner, he should relax, but this comes by avoiding over exposing him to to situations he is uncomfortable in

To the OP- there`s an Ignore button, if you go to the profile. It is very useful .

My advice to you would be to take a look at the hundreds of German Shepherds in rescue all over the country - many without even the tiniest of behavioural problems, and see how hard those ones are to home. Yes, a rescue probably would make space for this dog in question, and if they were fortunate, they could find a fosterer with the space, time and experience to sort this dog out, but it is far better all around, for the dog, the rescue, the fosterer to avoid this.
I have been in a similar place to OP with a GSD and to say I should've rehomed my dog is ridiculous. I had no experience of the issues my previous GSD had, but to give up a dog because you've not experienced that problem before would lead to hundreds more dogs in rescues. OP is prepared to go above and beyond what lots of owners would do - coming here and admitting she is struggling and asking for help is actually a lot more than some would do. If OP can put the work, time and effort in, it's far better for a dog to be "fixed" and stay in what seems to be a dedicated home, than passed around a rescue with issues that may only get worse with such a dramatic change in its life. I was not fortunate enough to have a forum like this to hand at the time, but I did everything I could and she could've easily ended up in a rescue kennel with her issues made ten times worse, never getting homed, because on top of her mental issues were expensive health issues.

That does bring me to another question for the OP though, has your dog had any health checks recently? I would certainly want an extensive checkup done to rule out any health issues, e.g. hip problems given his breed, as these could easily be aggravating a behavioural issue.

I am very sorry I am not able to give any advice on this, BUT!! I will say, listen and take notice of the GOOD advice on here, there are some very helpful and kindly folk who might be able to give you an insight of how to help your dog, without outdated and cruel means!!! without having to rehome your boy. There are a lot of people who have to go out to work and leave the dog home alone so dont feel guilty.

Hope you can get sorted.

xx

No matter what people think of the Mexican person, his methods work and all his dogs are all well behaved and not least he has saved thousands of dogs from being put down, being nicey nice, doesnt solve the GSD`s problem, avoiding things doesn`t solve the GSD`s problem, all the sympathy given to the owner does not solve the GSD`s problem, my reply was an honest answer intended for the benefit of the dog only, if an owner is at a loss at what to do, they shouldn`t of got a GSD in the first place, (I have owned GSD`s) we have no right to own dogs, it is a "privalige," one that should given to those who put the time and effort into making that dog as it was born to be, from day one. If the owner has the time and money to help the dog then good for her, I hope she does, if not, then the dog is not being "fulfilled" as that Mexican person would say! We as dog owners have to prove we can take care of our dog`s, which means having a good deal of knowledge before we have the "privalige" to own one. I dont mean to offend anyone in this forum, but we should all remember, that all unwanted behaviours are never the fault of the dog, it is always human error!!

How do you know Cesar Milan type treatment will solve the dog's issues? The owner has actually tried negative 'reinforcement' such as bark collars and these haven't worked. I too have owned GSDs - I grew up with at least 2 in the house, and I have barely had a moment in my life without one (have a big hairy lump of a GSD sat next to me now). Nicey nice does work - and the results tend to be more permanent that negative methods because the dog WANTS to behave correctly, because it knows that there is ultimately a reward for it. I think this is a much better method than teaching your dog to do things because it's scared it will be hurt if it doesn't. I have used positive reinforcement on Casper's reactivity. Within a few hours, at a workshop using positive reinforcement, we got him from barking and lunging at a stuffed toy stooge dog from across the side of the hall, to walking around in a figure of eight following the two other dogs on the workshop. All by using distraction and rewards for calm behaviour, not one "tssh" or strangulation (as Cesar has used for dog-reactive dogs - how can you justify that as training?) necessary.
As for CM's methods working and saving dogs, I have heard that numerous of his customers have had problems again after the show - because his method are quick fixes done to make good viewing.
If the dog's problems aren't the fault of the dog then why punish them for it? You can reshape all sorts of behaviours with positive reinforcement and get a permanent change in the dog. Why would you want to treat a dog with fear aggression with harsh methods that will just exerbate it's fears? I'm on another forum which has lots of rescues and rescue volunteers, fosterers, etc. and none of them use the "CM way" at all, yet there have been countless cases of turning around aggressive dogs using positive reinforcement to teach the dog that there is no need to be scared/defensive/whatever the cause of aggression is. As you have owned GSDs you will know that for a big dog, they are sensitive souls, and in my experience they respond to positive reinforcement far better than negative training methods. They're also a pretty stubborn breed, hence you tend to get more results by encouraging them to do something rather than forcing them.

As for the comment saying the owner shouldn't have got a GSD when they can't cope now, I presume you know absolutely everything about GSDs because you've owned them, and have a neverending fountain of knowledge about JRT crosses. If everyone knew everything about the breed they owned, or had instantaneous knowledge on complicated behavioural issues from the get go then it would eliminate the need for this forum really, and put hundreds of behaviourists out of a job. I'd rather see someone get a breed they have the basic knowledge of and ask when they get to something they're struggling to deal with than have rescues insist that new owners must practically have a degree in their chosen breed before they can adopt - there would be lots of dogs left wilting away in rescues should the latter be enforced.

Well said krlyr & Claire.

OP ~ please don't be tempted to go down the "leader of the pack" route with your dog. It's an outdated & completely flawed interpretation of dog behaviour. Yes, a dog needs a caring & understanding owner that is able to kindly explain the rules of the house & the owner needs to be consistent in teaching their dog what is acceptable behaviour & what is not allowed. But you don't need to use harsh methods or try to "dominate" your dog to do this.

Positive reinforcement is not simply a "nicey nice" way to treat animals!! It is a scientifically proved part of associative learning theory. The bonus of using positive reinforcement is that you don't scare your dog, or make nervous dogs worse, it creates a great bond with your dog & your dog will learn to trust you, nothing awful happens if you get it a bit wrong sometimes & the best part for me, is that your dog begins to really enjoy the training sessions & becomes more confident it its own actions .

I have a previously aggressive GSD. I`ve owned GSDs for 40 years. I`ve retrained dogs with just about every issue going. And all without feeling the need to dominate a small animal.
Have a read of The Dog Aggression Workbook by James O`Heare. Unlike some, this guy actually has qualifications in animal behaviour.
What area are you in? Someone might be able to suggest a trainer. I know 2 antisocial classes in my area who would help you without costing the earth or suggesting you grow a pair.

hi im sorry to hear u are having probs with your dog
have you tried asking some of the dog walkers around you with quiet natured dog to walk past you when your out with your dog and talking to him all the time the other dog is passing give him treats to keep his attentine on you if he barks or shows any aggression walk him away he thinks he has to protect you when he lerns that he does not have to do this he will stop as for the barking in the house do the same thing tell him no and do not let him to the door with you and give him treats when he is good and do not pet him when he is bad with powerful breeds of dogs you have to be firm with them tell them off when they are bad and make a big fuss of them when they are good i have a american staffie who will not show aggresson to other dogs and will not bark when the door goes or when people enter the house and this was the way i traind her hope this is some help for you

Sorry I haven't read through every post so you may of answered this.....but where do you live.

As here we have a place in Solihull which do classes for aggressive dogs only, on a Sunday Morning. The guy that does them is actually a behaviourist/trainer and has expereince with big/small dogs that are aggressive and is happy to train the handler with positive training and rewards methods

Is there anything where you live that offer that support