Dog getting along with dog?

A great way introduce dogs is to walk them together but I recommend you do it in a specific way. Start off by walking the dog that is more aggressive, territorial, fearful, or excitable a block or so back from the other dog. Continually redirect his focus to the handler using treats, and SLOWLY close the distance until the two dogs are walking side by side. A dog that is in an excited, alert, highly focused frame of mind usually can't be redirected anymore. They have to be removed from the situation or you have to know how to slowly de-escalate things. The only kind of correction that makes them stop is one that's more powerful than whatever is going through their head at that moment. It would probably have to be such a powerful correction as to be borderline inhumane. The trick here when introducing new dogs and one or both are not well socialized is to get to neutral territory, such as an empty park. Then find that threshhold of distance where the problem dog starts to get excited or stressed out, and back off of it just a little bit so he's only curious and alert but not overly excited. Then redirect him with high value food. Close the distance slowly until the dogs can be next to eachother but still coaxed to look at their handler for a food reward. IF the dog gets so fixated on the other dog that it doesn't want food, it's too excitable to work with and you need to slow down and back up. The trick here isn't to make the dogs like eachother or to bribe them to behave. It is to condition them to want to watch you more than they want to focus on eachother. Then once they're focused on you and you're calm, they will remain calm.