I'd be really interested in your opinion. Our Nero is almost 3yo now and recently I started noticing a change in his behaviour towards other dogs. He was always extremely sociable. He was never in a fight and there were no bad experiences with other dogs.
He always wanted to greet other dogs and I was often struggling to keep him calm and centred when we approached other dogs on the lead. We managed even though he often behaved like a 35kg puppy.
He is still sociable but when I walk him on a lead past another dog - he is showing off! He lunges and growls and barks... something he has never done before! His tail is still wagging and I'm sure he isn't aggressive but he does look quite intimidating - and of course other dogs react to it. Yesterday we met a couple of border collies who weren't impressed by his show. It was quite embarassing actually.
So for now I'm not walking him anymore with our other dog but on his own - it's just easier to handle and I don't want her to pick up this behaviour. And I have dug out his 'halti' again... and I thought we had left that stage well behind! *sigh*. Anyway I'll be focussing on 'look at me' and 'sit' when we approach other dogs.
But I'm really interested in what caused this sudden change in behaviour? I have two theories: Either he is growing up or having a recent addition to our family is somewhat boosting his ego. Roxy (our second dog) is very submissive and basically kisses the ground he walks on. OH thinks he is just getting a bit too full of himself...