Our dog (M, 2y, corgi) is starting to show more aggressive tendencies. He’s about 2 and a half. For the first (almost) two years, it was just him and myself and my husband, and he loved being the center of attention. In February, we brought home our second dog (F, 11 mo, mini Goldendoodle). Last night, our corgi snapped at my parents’ dog when we were over visiting, which has never happened before. There was a lot of snarling and biting from my dog, and my parents’ dog was just crying and it was awful. We pulled them apart, and things calmed down. My corgi has done this a few times with other dogs at the dog park, but what worries me is that the other dogs usually aren’t doing much, just sniffing at my dog, and then my dog starts getting aggressive. We stopped taking him to the dog park, or we go in the area where he is just by himself. This is a relatively new behavior (past 6 months), and I’m so worried about it continuing. We’re unsure if bringing our new dog home is a factor, but we’ve considered it. They get along really well most of the time (there’s been like 3 times where he’s gotten upset with her, which is not okay, but even this concerns me). We understand that this may be a reaction from my dog being anxious, but we want him to understand that lashing out like that is not okay. Also, rehoming is not an option for us. We love our dog so much, and just want to know how we can help him and try to improve/retrain this behavior. We are open to obedience classes if that will help.