Non-reciprocal play. This is when you see one dog trying to engage another dog in play, but the other dog is ignoring that dog by looking away, walking to a different play space or flashing their teeth at the dog. These are all signs that at least one dog doesn't like the other.
An aggressive growl will be accompanied by snarling and snapping, while a playful growl is just a sound, accompanied by relaxed body movements (no tension).
If both dogs are play bowing, bouncy, or seem to exaggerate their movements and vocalizations, it's likely a play session. Another good indication of play is sneezing. Dogs sneeze as a way to communicate to their play partners (human or canine) that they want to keep things safe and fun.
Start by establishing separate areas of the house for each dog using Dog Gates, Dog Crates or other equipment to keep them apart. Do not let the dogs interact again until both have a very strong understanding of the “Leave it” cue (see below). Above: Keeping dogs apart using a crate is a solid idea.
Dogs are inherently social animals that live well together in groups, but that does not mean that all dogs get along. Most dogs will welcome a new sibling, but it is not always smooth sailing.
If your dog has had limited exposure to other dogs, he may resist socializing with them. Aggression is a common symptom of a lack of contact with other dogs. To get your dog feeling more comfortable around his canine counterparts, start with dogs that you already know are trustworthy.
Play fight between dogs is only natural and should be allowed. It is a good exercise for your dog, a rehearsal for adulthood, and a good practice for socialization. However, play fights can sometimes turn into a real and dangerous fight.
Forgiveness brings stress relief.
Both tended to spend more time together after the conflict regardless of if they had an existing relationship. While it seems dogs do forgive after a fight, there's still a lot more to learn about reconciliation in dogs. In some multi-dog households, it doesn't always work out.
Don't Let the Dogs “Work It Out”
Years ago, people used to believe in letting dogs fight to work it out between them. This is dangerous for both dogs and for nearby people. Also, the dogs may never get along after such a fight.
They like to snuggle up close to one another and fall asleep
"If they are sleeping with each other and snuggled up together — really truly making contact with each other — then that's an obvious sign that there's true affection between the animals," Nelson explained.
The function of this behavior is to confirm a relationship rather than to settle a dispute. The more self-confident individual will muzzle grab a more insecure opponent and thus assert its social position. The more insecure individual does not resist the muzzle grab.
It can take up to one month for an old dog and new dog to really settle in and accept each other's position in the pack. If you want a second dog, you need to be ready to commit to this process and not panic.
Indications that your dog is feeling jealousy may include whining or vocalizations when you show affection for another animal or a person, pushing another animal out of the way to get attention for themselves, refusal to obey, and sometimes even signs of depression and a loss of appetite.
Signs that your dog's aggression or aggressive behavior is dominance related may include signs such as: Aggressive behaviors in response to verbal corrections. Aggressive responses triggered by eye contact. Attempts to herd other pets or humans using nipping.
Your dog is used to being your companion, and if there are other dogs that are taking you away, they are going to act upset, jealous, and even angry. This new puppy is also on their territory, and they may feel like their life is in jeopardy. This behavior is perfectly normal.
One of the common ways your dog will try to say sorry is by making “puppy eyes” or tucking its tail between its legs. Avoiding eye contact and lowering their ears are also common ways for dogs to apologize.
Aggressive behaviors such as growling, lunging, snarling, snapping, or biting are used as a means of communication and to resolve competitive issues or perceived threats. The competition may be over food, territory, attention from an owner, position in a pack or group, or as a protective reaction towards another dog.
You need to slowly approach and consistently praise him and be there every time he meets a new dog. Then throw in a neutral toy and encourage them to play. If either dog shows any signs of aggression, pull your dog away and wait until next time. You need to ensure positive, friendly play at all times.