There are certain breeds of dogs, like the border collie, that are easy to train. Herding dogs love to learn and they follow commands easily. Other breeds need more encouragement and guidance. If your dog already obeys the commands "sit," "stay" and "heel," then they should be receptive to the command to come in. Keep in mind that once your dog goes outside it is being exposed to a variety of smells and sounds that are hard for it to turn away from. However, with constant reinforcement and patience, you should be able to get your dog to come in on your command.
Select a training treat that you know your dog enjoys. These should be small bites as you will want to repeat the command and reward throughout the training process.
Choose the specific command you will always use. It should include your dog’s name and the command, such as “Duke, inside” or “Duke, come in.” Be consistent.
After you have let your dog out and it has completed their business call out the command in a loud and firm voice. If the dog responds by coming in, reward it with a treat.
If the dog doesn’t respond, go out and guide it into the house using the treat as a reward for their obedience. Repeat the process.
Practice the command and offer a reward every time the dog goes outside. It can only learn through repetition.