Puppies and even adult dogs can become so wound up, they can tip over into excitement aggression. That most often happens in the presence of multiple dogs when high arousal overtakes the group.
It's important to recognize warning signs or situations that potentially could result in bad behavior. Clueless puppies bring excitement aggression on themselves by acting inappropriately around other pack members. A “gang mentality” can potentially develop in groups of otherwise well-behaved dogs, when high arousal of one or more spreads to the entire pack.
Most aggression has a stress or anxiety component, which increases during pet introductions and in multiple dog households where dynamics often shift with age, health status, or living arrangements. To avoid or diffuse aggression, you should understand what triggers the behavior, recognize warning signs, and know what constitutes an “appropriate response.”
Puppy Excitement Aggression
Pups can become so aroused from happiness that their excitement turns into aggression. One of the most reactive areas of the home especially in multiple dog households is the doorway.
It's a dog rule that the one in charge gets to go out the doorway first. But clueless adolescent pups may be rude and try to rush ahead of the rest of the dogs (and you). That not only endangers people when a big pup (or pack) knocks them off their feet, the pushy dog believes the behavior puts him in charge. It sets a precedence so he may decide to control other interactions with you as well. Worst case, it can start a fight in the doorway among other dogs that don't take kindly to the puppy's rude behavior.
Predict and Prevent Problems
When you expect guests, separate the dogs. Use different rooms or crates until visitors have settled. Arrivals and departures with opening and closing doors, can be very exciting for dogs so keeping your pup away from this excitement goes a long way toward preventing excitement aggression. Once guests have taken off their coats and chosen a chair, you can allow the pup to meet and greet.
Another way to manage the excitement is to associate the opening and closing of the door with a behavior that prevents confrontations. For instance, each time the doorbell rings, that could be the signal for the puppy to sit and stay, and then receive a treat. Or you can teach your dogs that the doorbell means he should search for and bring you his ball, for a game of fetch. A pup with a ball in his mouth and play on his mind is less likely to pester the other dogs into a skirmish.
In these situations, it will help greatly if the pup also understands the “wait” command. “Wait” is different from “stay” because wait means your pup can’t move forward until you give permission while stay means don’t move in any direction until released. This reinforces your position as leader, and also helps your dogs learn deference and polite behavior. It can prevent arousal and doorway excitement that sometimes leads to aggression between dogs. You can use a combination of leash control and natural dog body language to teach the wait command, but you should only train one dog at a time. Learn how to teach your puppy to "wait" here.
Once all of your dogs have been individually trained to wait, teach the group wait, beginning with two dogs at a time. That can help prevent them from racing each other through the door.
Say, “dogs wait.”
Give the “okay” release to only one dog at a time, and alternate who gets to go first during these sessions.
Initially let the dog who does the best “wait” go first. Dogs catch on quickly, and you’ll love it when your pack competes to see who acts most polite to win the preferential "out the door first" reward.