Dog owners’ problems with their pets can often be attributed to a lack of dog obedience training.  Bad behaviour and training problems are often the result of insufficient physical or mental stimulation. A bored dog, or one that does not have his energy directed into something constructive can display numerous undesirable behaviours.  Destructiveness, barking and howling, and being generally unsettled are all behaviours that regularly occur. An untrained dog is likely to present all sorts of problems when out on a walk.  Owners commonly experience poor recall, chasing (of livestock, cyclists, joggers, children etc) or jumping at people. Your best friend may become unpopular with fellow walkers if he performs these behaviours.  Finally, you could be prosecuted under the Animals Act or the Dangerous Dogs Act.