Have you ever heard your friend saying that my dog was sad today or my dog comforts me whenever I am feeling a little out of place? The emotions verbalized by dog owners seem like they come from a real place. For instance, your four-legged friend always wags his tail when you come home. Or else your dog starts growling when a stranger approaches. We interpret the former as your dog is happy to see you, while the latter as your dog is protective of you.