To stop one dog from bullying another, it’s best to work with your dog in a controlled environment, like a fenced yard, instead of in a park where the amount of open space and the opportunity for other dogs to intervene can delay the process. For this exercise, select a confident playmate that can tolerate canine misbehavior and won’t get triggered by your dog’s pushiness. Put your dog on a long, light leash before the play session begins, this “drag line” allows you to enforce the time-out without having to put your hand in between the dogs. If your dog starts off by interacting politely with the other dog, praise him for his good behavior and allow them to continue playing. If your dog has a super-strong recall, occasionally call him to you during the session before things get out of hand for occasional “de-escalation” breaks, during which you praise him and give him a small treat. The moment the other dog looks stressed or like he’s trying to get away from your dog, use your time-out phrase to mark your dog’s behavioral infraction, then pick up the long line and lead your dog away from the fun. Take a 30-second break during which your dog has no exposure to the other dog. With enough pairings of the phrase and the time-out, your dog should start to realize that every time he’s inappropriate with his playmate, the fun stops. Praising your dog for appropriate interactions and taking well-timed behavior breaks should help even the most harassing of hounds figure out that fair play is the way to go.