Dogs can’t use words to express themselves the way people can, but that doesn’t mean they don’t communicate. Dogs use their body language to tell us how they’re feeling and what they need.
The most commonly known form of dog body language is a wagging tail. This is often interpreted to mean that the dog is happy, but this is not necessarily the case. Some dogs who are happy don’t wag their tails, while others who do may be wagging their tail for other reasons, including aggression, according to www.aspca.org. The position in which a dog holds its tail can also be an indicator of its mood: a relaxed dog will hold its tail in a neutral position, while a dog who is feeling threatened or sad will lower its tail. Dogs move their ears in similar ways; when a dog is alert and excited, he will raise his ears.
Like animals in the wild, dogs try to make themselves appear smaller or larger when they feel threatened. You can tell that your dog is scared when she tries to make herself look smaller by hunching her body or lowering her head. An especially scared dog might even roll over on its back as a sign of submission. When a dog is feeling aggressive, it will try to make its body seem big and intimidating by stretching out its neck and leaning slightly forward.