One very important thing for every dog owner to remember is that the dog is a living being. It has its own predetermined patterns and reasons regarding behavior. Most dog owners think of their dogs as members of the family and forget that the domestic dog is a very different organism from the human. As such, the dog's emotions, thoughts and actions can appear mysterious, "spiteful", and even outrageous to its human companions. In fact, the domestic dog is quite a simple entity and can easily be understood.
When a sudden behavior problem erupts in a dog's daily routine, the owner is likely to interpret it in terms of human motivation. "My dog is angry at me for getting a full time job. Out of spite, she is peeing in the house every day." Nothing could be farther from truth. Dogs do not choose behaviors out of "spite" or "anger". Dogs are rather motivated by factors that precipitate behaviors as their genetic predisposition calls for. For instance, a Shetland Sheepdog (Sheltie) might nip at the heels of the children. This is not a choice of behavior for the Sheltie, it's simply its genetic predisposition to attempt to control moving objects. In another instance, in a multiple dog household the dog with the strongest personality dies, leaving the other(s) to sort out who is who in rank. This might bring about separation anxiety, causing the remaining dog(s) to inappropriate urinate/defecate, become destructive or mischievous, seemingly out of nowhere. However, the remaining dog(s) have very good doggie reasons for the way they behave!
Before a dog owner throws up his or her hands in dismay and disgust because of sudden behavior problems, s/he should carefully look at the world from the dog's viewpoint. What has changed recently? Who has moved in or out? What is happening between human members in the household? Is the dog healthy and free of intestinal parasites? Is the dog's diet possibly the cause? There are many down to earth and perfectly understandable reasons for most problem behaviors in the domestic dog. Think DOG before deciding that your trusting friend needs another home! If you are facing a serious problem, such as aggression, find a certified Behaviorist rather than a dog trainer. No amount of obedience work is going to change a dog's behavior once it has begun to demonstrate aggression, and most aggression in the domestic dog can be eliminated!