Ever seen a dog flick their tongue and vibrate their jaw after sniffing something interesting? This is called the Flehmen response. It's a special technique dogs use to enhance their sense of What Really Causes Your Dog to Sleep With Its Tongue Out? Your Pets at Home Dog Teeth Chattering: Causes and What To Do PetMD Did you know your dog's tongue can reveal how hot they are? @passionatelypets shares four tongue shapes to watch for during warmer weather: Cool & Comfortable: When a dog is relaxed