Some dogs do well with their training until they encounter a new situation. They may become aggressive with other animals or people. If your dog becomes aggressive, this behavior cannot be tolerated. Responding with violence will only make the situation worse. Some things that you should try include removing your dog from the situation immediately. Tell him no, to let him know that you disapprove of the behavior. It’s important to deal with aggressive behaviors swiftly and consistently.
Training takes practice, and the more time and effort you put into the process, the more you will get out of it. If this is your first dog—and even if it isn’t—you may want to consider hiring a private trainer or think about signing up for a training class. Puppies usually start out in puppy kindergarten. After that you can join an obedience class for older puppies. Class size for puppies should be limited to eight to ten dog-and-handler teams per instructor. This ratio enables the instructor to give each team enough attention and time to respond to questions or special training circumstances.
Just as you would with a new puppy, you should introduce your shelter dog to crate training as soon as possible. In this way, you can work on housebreaking and be comfortable that he won't get into mischief when left unsupervised. It's also helpful because it gives your shelter dog a place of his own. Between living in a shelter and now coming to a new home, your dog may feel extremely stressed. Having a place of his own to retreat to when he feels overwhelmed can go a long way in helping him get settled in his new home.
Don’t overwhelm your dog by expecting too much at first. Start slow by working on basic commands, such as “sit,” and keep training sessions short. You can gradually train your dog for longer periods of time and move on to more complex commands, such as “leave it,” once basic training is successful. As your dog learns these basic commands, it becomes easier to start training your dog on the more difficult ones.