One of the most common and frustrating behavior disorders in dogs is separation anxiety. Most dogs experience some stress or anxiety when we leave them to go to work or school. After all, they are pack animals, so being left alone all day does not come naturally to them. Despite this, most dogs adapt to our absence, spend a good deal of their day sleeping, and then are overjoyed to see us when we return. A dog with separation anxiety exhibits signs of fear during the owner's preparations for leaving the house. He may pace, drool, whine, or follow his owner all over the house. After the owner is gone, the dog may be destructive (possibly trying to escape the area in which he's confined in order to find his owner), he may urinate or defecate in the house, he may bark or howl excessively or he may do all three of these things.