Dog's bad habits are a common thing and very often result from an inappropriate training or lack thereof. Many folks out there do not devote enough time to their pets and often leave them alone for entire days (because of the work duties etc.). This fires back at them when their pet gets older and becomes hard to control, especially if he has been reinforcing the bad habits for a few months/years already. However, with an appropriate training program dog's bad habits can be alleviated quite effectively, providing that one knows what's causing them.