I have a 1/2 Blue Heeler, 1/2 mix male puppy who will be 1 on Jan. 18th. HIs name is Levi. We got Levi when he was 9 weeks old. He's a rescue who was born into foster care with 8 siblings. We socialized him a lot right away and he was socialized in foster care as well. He attended a 6 week puppy class very early on and played with several other puppies with no problems. He has regularly seen/played with older dogs since we've had him. Around 10 months he snapped at a younger puppy. It was immediate on meeting the puppy, in other words the puppy didn't have an opportunity to be over the top in his face and then he corrected it. It was more like he met the puppy head on with a snap. I pulled him right back and scolded him, I didn't hit him or anything like that, but he knew I was unhappy with him. We tried again and the same thing happened but this time the puppie's owner kicked him in the face. Not a good scene. A couple of weeks later he did the same thing with another puppy that came up without asking us if it was okay and we were caught unaware. We just pulled him away and didn't scold him. Then a couple of weeks ago he did it again with a very young puppy. This time I pulled him back and spoke softly to him, I petted and praised him for being calm and we tried again and he was good. Both subsequent puppy meetings were the same, immediate snap right off the bat. He's in regular classes now and sees other dogs. He's doing well. One thing we are trying to conquer is how excited he gets when he sees other dogs, like on leash passing on the sidewalk. His tail is wagging the whole time and I get the sense he just wants to run over and play. He seems to be very smart and is getting better. I praise him when he's calm and just turn away in the opposite direction when he can't contain himself. I work on it as often as I can. It's 2 steps forward and 1 step back. I'm wondering if that first bad encounter with the puppy set us up badly and that's what we're dealing with in regards to the other puppies. And is this connected to the anxiety/excitement with other dogs? Just additionally, he's very, very sweet, and he loves people. He's very happy. I don't feel like we have a huge aggression problem. Just looking for advice on how to work with this. Am I on the right track? Thank you.