@tanza:
Again, I disagree
You make it seem like it is a natural and logical thing to do for a dog.
Reading the commends here, they do it when excited, when displeased, when nervous…
It's not that once a dog get's into a different state of mind, that he forget's the world around him. Knowing what's happening around them is one of the strongest instincts in a dog, simular to hunting instinct. Their survival depends on it. Except in cases of extreme fear, a dog never stops watching what's happing and will allways be allert.
Let's take Kipawa's examples. Don't seem situations in wich the dog would be so excited he forgets the rest of the world. The 3rd example she mentions, they just met a woman with 2 dogs on leash. So what could trigger the behavior there? Excitement propably not, displeasure also seems weird, nervous the same... I'm pretty sure that there, the dog knew pretty well what he was doing and that it was most likely a sign of dominance. The dog saying 'look what I can do, and it's so easy, ain't I the best?'.
Examples in the show ring. Maybe your dog get's really excited, but still, lifting his leg against yours, is still a sign of disrespect. Some people here said they reacted, and he did it just once. But according to what you say, they would get so excited again next time, that they again go into an other state of mind, forget all what's around them, and would do it again, cause they aren't aware of it when they do it.
In dogs is not that abnormal to establish dominance that way, and you have to teach them that it's not OK when they do it with humans. And they way I see it, if your dog tries to do it with his owner, something in the relationship between the 2 of them isn't what it should be. You aren't clear enough to your dog, he doesn't respect you like he should, bonding is not optimal and it's then just one of the many ways your dog can make that clear to you, so you know you got to do something about it. And this is a behavior that you can work on and that can be solved. Not something that you just have to deal with because the dog can't help it.