Dakota
You'd never infer it from this picture, but huge Dakota, a sweet, loving dog to people, was fiercely aggressive toward dogs he didn't know. His owners were at their wits end about how to stop this behavior, which was causing them a high degree of stress and a lot of liability. They had tried everything, including other trainers.
They were eager for me to answer the same question everyone asks about people-aggressive and dog-aggressive dogs; Can he change?
I gave them my stock answer: Yes, but a range of outcomes is possible depending mostly on him and you. I've never had a dog worsen, I said, and sometimes they get over the problem completely. At other times the dog will improve significantly but will need careful monitoring and clear leadership. The goal is improved behavior and reduced stress and risk. I assured them I'd coach them during the follow-up phase.
I've found that most dog-aggressive dogs are not inherently mean; they are mostly inexperienced and under-socialized and simply need a lot of experience under the care of someone who knows how to handle such dogs while showing it that meeting other dogs can be fun. But how does a person put his aggressive dog, especially one as massive as Dakota, around other dogs without dogs and/or people getting hurt or killed?
My approach is to use a basket-style muzzle that allows a dog to opens its mouth, pant, and drink but prevents it from biting. This also reduces the owners' stress and keeps them from projecting that stress onto their dog. Also, at first I always keep a leash on the dog so I can pull it away if any dogs shows signs of a fight. (Their body language always indicates an altercation is brewing long before a fight breaks out.)
The first couple of weeks were tough. Dakota would lunge at new dogs, and pulling him back took all my strength. How, I wondered, would his female owner, a petite young woman, possibly handle him physically? But he couldn't hurt a dog wearing his muzzle, and I took him everywhere we would encounter them: town, dogs parks, well-traveled trails. Slowly he began to greet a few dogs without going full Cujo, but his trigger was always cocked. It took hundreds of interactions, but he began to learn that he didn't have to respond aggressively when meeting. He began to show signs of enjoying the interactions. Eventually I could take him anywhere, and was confident enough to remove his muzzle. But the moment of truth was approaching.
When his owners picked him up, we had another straight conversation about the importance of their leadership. The look in their eyes told me they'd cowboy up and do their best.
The man had a pretty good handle on Dakota, who weighed almost as much as he, but Dakota pulled his wife like a waterskier. But she refused to give in and dug deep to make sure Dakota knew she was his leader and acting aggressively was no longer an option. They both learned to reward positive behavior and read Dakota's body language to prevent problems.
We practiced around new dogs. Even took Dakota to the dog park where multiple dogs, some of which had poor social manners, ran and played. Slowly, Dakota began to behave for them as he had for me.
We met a few more times over the next weeks, and I remained on call to answer questions and provide coaching. And the last I heard, Dakota was walking in his neighborhood and other public places without incident. His owners were no longer stressed and worried.
Dakota's was a serious red zone case, and it was mostly a success not because of my work but because Dakota's people were willing to rise to the challenge, accept coaching, and put in the work. Again and again I have learned that that makes all the difference.