barking at people

Hello there []

Now, if you lean back and read your post over again, I am sure you will notice three things: 1. Your dog does a lot of things, but not display 'protective aggression' (at least not judged by what you write). You say yourself that he does not display typical aggression signals. 2. If someone snuck up on me from behind in the dark, I would bark too if I were a dog, and I probably do some people-equivalent of a well-socialized human. It might be helpful to teach him a calming signal, that assures him that you, the leader, has seen the situation and has it all under control. 3. You seem to say that he is well socialized, so another explanation might be that he just asks these people to play with him (now theres a strange thought for a Lab/Golden mix!) when he is not explicitly ordered to do otherwise (as he is, for instance, when put in a sit/stay).

Given this view of the issue, why not train him to simply behave different in those situations. As it is no easy feat to train a dog to sit/stay on a busy road while one is gone, I am sure you can also train him to stop jumping around unsuspecting strangers! []

If he is a GSD mix, I would not be surprised that he barks at people coming up from behind.  GSD's, like many of the herding breeds, have a habit of liking to keep "all the butts together", meaning their livestock where they can see them.  If you aren't there, he has no livestock to herd LOL.

polymatheia:

hi and thanx for your input.
I wouldn't say that he is friendly, his "friendly bark" is different, higher in pitch and with more pauses. His behaviour in these situations is more similar to behaviour toward thing he is unfamiliar with or cosiders strange/possibly dangerous. I do not say he does not display agression signals, just not "dominant agression signals".
He is well socialised, but not to people he considers "sneaky". How do I go about teaching him to calm down? At home, he sometimes barks at strange noises outside the door and it helps if I get up and take a peek at the door, then look at him saying "that's all right" , but I have not really established "stop being alert" signal.
I do believe he can be trained to stop behaving like this, I am just trying to figure out how (training to sit-stay is a common matter and you can read about it everywhere. so I have. and it worked.) The only reference I found for this was a site about "protection work". I suppose I could go to a class that teaches protection, but I am really not interested in teaching "become alert", only "relax" part of it
Today I managed to stop him from barking while I unattach the leash by not releasing him from sit-stay till finished

spiritdogs:
He still has unsuspecting passers-by to herd
Besides, he doesn't herd me, he rather has a tendency to place himself either in front of me or between myself and the perceived danger

Well, don't necessarily flatter yourself into thinking he is guarding you.  Oftentimes, it's just the dog thinking that you aren't able to handle the "threat" for him that puts him out in front.  Without seeing your dog, it's difficult to tell.  If you really want to know what's going on, get a trainer to observe you in person.
As for a command that tells the dog to not be on alert, that's very difficult.  It would be as if I told you, "Even if you think a rapist is coming in the door, don't react".  If you thought it would be in your best interest to do so, you might, but on the other hand, panic might set in and force you to scream.  Dogs are hardwired to behave in certain ways, and to be honest, I would not want to extinguish my dogs' alerting capabilities.  Instead, what I have done is to teach a command (that'll do) that means - ok, you barked your three warning barks, now be quiet.  I also try to call my dogs to my after they alert.  If there was a real threat, we'd be out the back door together!  Doing that also helps the dog to see that you are pleased he alerted, but now you need his attention for the next command, since you are in charge.

Lol... that reminds me of a saying in our country: "a dog does not bark for the village, but for itself"
I know that he would desist if I scared the bad guys away and would feel more secure with me, but that is not easily done (as I am not very scary). When my sister's female dog (that my dog is dominant of) feels threttened by other dogs he jumps in without hesitation and scares them away. So I suppose this is what a good leader does.
I have put him on a stricter, more NILF regime, so that might help. Also, I try and have him walk a step behind me on leash, which seems to help keep him less in charge when strolling down the street.
I was able to teach him not to charge other dogs by demostrating that we can just go away or around them, so this may be another thing to try.
I'll also try your 'That'll do" approach, practicing first on home possible intruders i.e. my neighbours making funny noises behind the door and see if it can be transferred to "out of home" perceived dangers.
thnx.

Seems you are well on your way. Good going! []

Just a suggestion, but since he is a mix, why not consider neutering him?  

I have ethical objections to doing so. I would love to discuss that, but I assume this would be offtopic here

It isn't OT to discuss neutering as a partial solution for a behavioral problem.  One of the primary reasons for a 21 month old unneutered male dog having problems with other dogs is that he is exhibiting male secondary sexual characteristics.  And, the fact that you think he no longer has problems with other dogs may simply rest with the fact that he has not since met any other intact males of similar status with whom to disagree.
As to the barking and jumping, I'm thinking that he could simply be displaying leash frustration or simple reactivity (usually based in fear, not aggression - and due to the knowledge that when leashed, the dog cannot escape to give himself enough personal space between himself and the "intruder").  This is often a handler perpetuated problem, so learning to deal with it in appropriate ways might help - Ali Brown has a nice little book called "Scaredy Dog" you might want to read.  Or, Patricia McConnell's "Feisty Fido".
As to ethical considerations, I feel that's an outdated attitude, considering the millions of homeless pets.  If your male should get loose and mate with only three females while he is gone, it is possible that as many as 3-36 puppies could result.  If you have no ethical objection to euthanasia (those pups displace some dogs already waiting for homes), then perhaps it's fine that he is intact:-((
 

ORIGINAL: spiritdogs

It isn't OT to discuss neutering as a partial solution for a behavioral problem. One of the primary reasons for a 21 month old unneutered male dog having problems with other dogs is that he is exhibiting male secondary sexual characteristics. And, the fact that you think he no longer has problems with other dogs may simply rest with the fact that he has not since met any other intact males of similar status with whom to disagree.

Yes, I agree that his dog to dog problems are due to his not being neutred as they follow a typical pattern. And yes, when I say he got better, I am serious enough about that claim. So, to calm you: we see other intact males regularly and my dog is behaving great with large majority of them and we avoid the others.

ORIGINAL: spiritdogs
As to the barking and jumping, I'm thinking that he could simply be displaying leash frustration or simple reactivity (usually based in fear, not aggression - and due to the knowledge that when leashed, the dog cannot escape to give himself enough personal space between himself and the "intruder"). This is often a handler perpetuated problem, so learning to deal with it in appropriate ways might help - Ali Brown has a nice little book called "Scaredy Dog" you might want to read. Or, Patricia McConnell's "Feisty Fido".

Barking and jumping happend offleash on two occasions and onleash only in tied to a post/released from sit-stay situation. When he is on leash and we walk, he does not do that, he did that a few times while sitting on leash, but in these cases there was no leash tension. Also, leash tension does not happen very often, as he doesn't pull, and is very responsive to any tension in the leash. (we cannot use extendable leash, as the pulling effect in it is considered "correction" by my dog

ORIGINAL: spiritdogs
As to ethical considerations, I feel that's an outdated attitude, considering the millions of homeless pets. If your male should get loose and mate with only three females while he is gone, it is possible that as many as 3-36 puppies could result. If you have no ethical objection to euthanasia (those pups displace some dogs already waiting for homes), then perhaps it's fine that he is intact:-((

I think it would probably be in the best interest to both of us to refrain from name-calling. The possibility of my dog "getting loose" is minimal. Perhaps it could also be reduced by chopping his legs of?