Teaching a dog to come when you blow a whistle is a great idea! The whistle can act as an “emergency” fallback signal if your dog can’t hear you calling in a noisy environment, for instance, or when the dog is very far away.To teach a dog to come to a whistle, start by standing in front of your dog inside your home. Blow the whistle, then feed them five to 10 tiny treats in a row, right in their mouth. Wait 30 seconds, then repeat. Do this twice a day for a week. After a week has passed, repeat this process but stand further away from your dog (about three feet). Most dogs will step toward you. Once they begin moving your way, start to hand feed your dog their treats. (If they do not come to you, then go back to standing in front of them.) Continue this process, gradually increasing the distance between you.