Dogs will not necessarily get sick if they are bitten by mice. If the mice carry bacteria, they may be infected with rabies or tetanus. Therefore, it is best to clean the wound in time and then send the dog to the pet hospital for examination. You can use saline or hydrogen peroxide to clean your dog, which can have some sterilizing effect. And it is best for dogs to get rabies vaccinations in advance, otherwise they will not be cured once infected.