I think I've posted about this before-- but I'm looking for more info. I adopted Archie last December, after fostering him for about 5 months. He's 10 years old. He's improved with other dogs, but this is where we're at now. Other Dogs in the home, and dogs that belong to my friends that he's familiar with, He tolerates. He doesn't submiss, he doesn't dominate, he just ignores. He could care less. With him, there is barely pack structure. The other dogs ignore him just the same. With friend's dogs, he can tolerate them, but if they annoy him, get in his face, or obnoxiously bump him he'll put his ears back, raise his lips, put his head in the air, widen his eyes, and growl. Sometimes if it's bad, Open mouth warnings, so to speak. It never lasts. He just moves away and that's it. He's never bit down on another dog, except for when one of my foster dogs ( 70lb shepherd) mounted him. I kind of feel that was warranted That's handled easy enough-- But in the store, or around strange dogs, his behavior is hard for me to read. He can walk with me just fine, and ignore other dogs in the vicinity. Probably up to about 5 feet away. He may stop and look, but then continue right along. He's pretty good with focus work, It's very easy for me to get his attention on me. He will stay with dogs walking near him. But if we're closing in on a dog, or the dog is walking towards us whining or barking, he'll perk his ears up as if he's interested, and try to pull towards the dog. Once he gets to the dog, he'll immediately open his mouth and "RRrrrrr!!" over the dog. Ears back, tail down normally. It's some sort of aggressive warning thing, I don't know. There's no lip-lifting or growling or warning of any kind. This reaction really only happens every once in a while, if he's worked up. He'll get excited when he sees another dog, I can see it in his posture. Sometimes he'll go greet the dog by sniffing it's face, and then turn to me for a reward. The way I've dealt with his "aggression" is by working on focus, ignoring, and rewarding him for all good behavior around other dogs. And nice greetings. If he's getting worked up, I will simply walk him in the other direction, and he's fine. Sometimes when he sees another dog, being crazy, he'll get tense, then turn to me and sit right down, purposefully ignoring the dog to get his reward. I fear that maybe through rewarding him everytime he politely looks at another dog, he gets too excited when he sees one. I'm just not sure how to treat this behavior, I can't really read whether it's anxiety/fear based, or just plain aggression. His behavior seems mostly nervous, especially around the more familiar dogs. What does it sound like? Should I videotape his behavior? I can't afford a behaviorist, but it doesn't matter since It's not affecting either one of us at all. All of the above described behavior is very mild, at best. He's in Pet stores with me at least 4-5 times a week.