How to Decode the Movements of a Dog's Tail

The movements of your dog's tail tell you a lot about his mood and level of comfort. Dogs tend to wiggle or wag their tails to be social when other animals or humans are around. Even though your dog is wagging his tail, how high he raises it and the speed of the wagging also play a role in decoding his emotions. Learning to decipher various tail movements allows you to understand your dog and predict how he may react in an unfamiliar setting.

  1. Height

    • When you get home from work, take your dog for a walk or give your dog a treat, he probably holds his tail out horizontally and wags it from side to side. A horizontal tail is the sign of an alert, happy, attentive pooch. If you bring a strange dog into your home, your dog may lift his tail up high in a vertical position. This vertical position can be threatening and used to alert other dogs that he is the top dog, explains Dr. Stanley Coren, a psychologist specializing in animal behavior. A vertical tail may mean that your dog is ready to pounce or attack. When your dog is afraid, submissive or fearful, he lowers his tail toward the ground or may keep it between his legs.

    Happy Wag

    • The speed of a dog's wagging tail is another important factor. Gentle, narrow wagging is his way of letting you know that he is nearby. It signals that he is comfortable and wants attention. As he gets more excited and ready to play, he will wag his tail more quickly and in a broader motion.

    Nervous Wag

    • When your dog is a little nervous or insecure, he might stick his tail straight out and wag it cautiously from side to side. You may notice this movement when you take him to a place that he is unsure about. If your dog is in fight mode, you may see a high-speed wag or vibrating tail. Be especially cautious if he holds his tail up high and wags it rapidly. It can be a sign that he is ready to fight or to run away.

    Asymmetry

    • A 2007 study conducted by veterinarians at the University of Trieste in Italy and published in the Current Biology journal, looked into the asymmetry of a dog's wagging tail. Researchers noticed that a happy, attentive dog wags his tail more toward the right side of his body. The left side of the brain is associated with positive thoughts and emotions. Since the left side of the brain controls the right side of the body, your excited dog wags his tail more toward the right side. The opposite occurs when your dog has negative feelings, since the right side of the brain controls the left side of the body. When your dog is scared or nervous, you may notice his tail wagging more toward the left side.