Because dogs are social animals they instinctively seek a companion. When left alone dogs can suffer from a condition called separation anxiety. Generally, almost every dog reacts when his master leaves the house. For some dogs however, the reaction is so intense that they need to be addressed for the benefit of the dog and its master as well. Signs of extreme anxiety in dogs are incessant barking or whimpering, digging, chewing, hyperactivity, vomiting, urination or defecation, and destroying things around him. In some cases, dogs can even go to the point that they would hurt themselves when left alone.