My 8.5 month pup Bogard, had a disturbing scene at the dog park today. He doesnt ever show aggression nor does he ever just bite and pull on people's pockets.....Today he decided to go after 3 different people's pockets and wouldn't let go until i pulled him off them....he didnt hurt anyone, but it's kinda scary. They didnt have treats in there pockets either. I'm not sure what's going on with him as of late. I should mention we have him enrolled in his second series of obedience training. And now that I think of it we had the same episode at training on tuesday. I had to pull him off, say no, and give him a timeout. Timeouts dont seem to work with him though, as he remains so focused and will just go back to doing what he was doing. What else can I do?