Excerpted from Decoding Your Dog by Debra F. Horwitz, DVM, DACVB and John Ciribassi, DVM, DACVB For dogs and humans alike, physical exercise is fundamental to good health. We all know the couch-potato lifestyle comes with a host of health problems. But in dogs, a lack of activity can also prompt nuisance behaviors. The majority of dogs were bred with a working purpose in mind - and that's not just the herding and hunting breeds. For example, the seemingly dainty Yorkshire Terrier was originally meant for rat hunting. Providing dogs with vigorous, daily exercise has profound effects on their behavior. Tired dogs chew less, bark less, sleep more, and are more likely to relax when home alone. A good daily workout and, if the dog is social, regular play sessions with other dogs are great ways to exercise a dog. So is time spent interacting with his owners, whether that's playing hide-and-seek in the yard or coming along to the office. If, like Anna's rowdy, a dog gets hours of exercise every day and still tears through the trash or disembowels the bedroom pillows, it's safe to assume he lacks mental stimulation. Much as people turn to crossword puzzles, books, chess games, [...]