There are five common groups of canine communication signals. As you review the groups, please keep in mind that in a given situation a dog can demonstrate more than one of these groupings in response to the situation. For example, a dog may begin by displaying excitement signals in response to a stimulus, decide that stimulus is a threat, and switch to aggressive signals, fear signals, or even both. Also keep in mind that stress can drastically influence a dog’s response to a given situation. Again, we must look at the whole dog and his body language, as well as the situation/environment in order to get the “big” picture of what the dog is communicating, what may happen next, and what our appropriate responses should be.