Hello, I am new here and the proud owner of a 7 year old yellow lab mix. He's a wonderful dog, just...quirky. Okay, he's a mess (but he's my mess). One of his more worrying issues is unpredictable fear aggression. Out in public, he ignores most people, but sometimes randomly lashes out, always in fear. The people span all genders, races, ages, and personalities. I am very diligent: I keep him close, steer clear of crowds, ask people not to pet him, and always have a muzzle just in case. But ideally I'd like to solve this problem or at least know what he's scared of. Any ideas?