There is really no rhyme or reason to it. Sometimes it is directed towards other dogs, but other times he is totally friendly towards other dogs, and still other times he seems timid/fearful but not aggressive. He has never had a bad experience with another dog, and I can't see any pattern in the behavior. Same thing with inanimate objects. Every so often we'll come across something on a walk that he is leery of, but sometimes he will behave in a very aggressive manner towards an object (two examples being a statue in a park, and a plastic shopping bag blowing across a street).
He has not yet behaved aggressively towards a stranger, but he does act timid quite a bit. He has only had positive interactions with people, and I don't force them on him or anything.
Just yesterday he got a leg wrapped-up in some twine while outside. He was obviously stressed/frightened but not in any real discomfort, yet when I tried to help him he mauled me. I'm not talking about playful puppy biting or gentle mouthing. I'm talking full blown skin puncture and bruising kind of biting. It just seemed to me, in that moment, that his "intent" was different. I had to hold his mouth shut and pin him between my legs while he thrashed around trying to bite me just so I could unwrap his leg.
I am concerned about seeing this kind of behavior in such a young dog... especially in one that has never been abused, attacked, neglected, etc. He spends lots of time with the family, gets 3 walks every day, and we try to take him with us when we go places. What concerns me even more is that his fear/aggression is inconsistent.
I'm not sure what to do. We have 3 young children (ages 12, 7, and 4), so our tolerance level for risk is relatively low. I feel like we've done a lot right with this puppy... lots of exercise, socialization, teaching basic manners/commands, etc. I guess my questions are:
1) How likely is he to improve as he gets older? Stay the same? Get worse?
2) How likely is he to begin showing fear aggression towards strangers? What about family?
3) We live in a city. Is our environment (lots of neighbors, cyclists, dogs, cats, yadda yadda) too stressful for him? Would his behavior improve if placed with an owner who lives out in the country or something?
Frankly, my knee-jerk reaction after what he did yesterday was to have him put down... but I don't want to make an emotional decision.
Thanks for any help and insight.