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 Why Dogs Sleep with Tongues out : Shedding Light Woof Blankets Dogs will flick their tongue as an appeasement signal but also as a signal theyre relaxing. While similar each signal has subtle differences. I will do posts on both. , The tongue flick is a signal Why Does My Dog Stick His Tongue Out? Causes Explained