Hi, can anyone help. Kendall is coming 2 years old and generally loves people, he is fine in busy places and takes everything in his stride. However a few times in the last couple of weeks he has seemed really frightened of someone and runs barkwards and barks at them. I'm not sure if its the surprise element as the few times have al been times when someone has stepped out from behind something unexpectedly, yesterdaywhen someone suddenely shouted and raised his arm, and today a woman very quickly got off her bike and approached him very quickly. I have tried to settle him but he is in panic mode till we walk off - any ideas?? He is also barking more at things in front of the house but I think a lot of dogs do this so am not as bothered aout this. Any deas as to why this has happened and what I can do?