Barking is a dog instinctive behavior, part of its way to communicate his emotions to other dogs or to the members of its pack. When dog barks from time to time it cannot be considered a behavioral problem, but if it becomes an obsessive behavior, repeated over time, it must be controlled.
1) Attention request: dogs want its owner attention to show him something that is unusual or because they want to get attention from him. The owner sometimes reacts angrily and shouting asking to stop to the dog, instead of stop barking, the dog reinforces the behavior because it interprets the yell of the owner as a “social howling”. Even the punishment, like a pat or any kind of contact reinforces the barking behavior, in fact, if the bark means “I need your attention”, the reaction of the owner will be exactly what the dog wanted. Rarely barking can impute to a food request, indeed it usually becomes a motivation when the bark is reinforced with an award from the owner. In fact often the owners hearing the dog barking, in order to calm it, gives him a treat, this behavior can be considered wrong because reinforces the behavior just ran, so in the dog’s mind barking will be associated with the administration of food.
2) Request for help: the dog can bark in order to request help because of hunger (real), thirst, heat or pain.
3) Excitement and frustration as an outlet How to control the barking dog First rule is not to reinforce it! If the dog barks the best thing, after excluding physical problems, is ignore it. The dog is a social animal that does not like loneliness, thus reducing the reasons to request attentions, they will be reduced consequently also episodes of barking. The excitation can be controlled by socializing the dog to stimuli, the more the dog will know things the more it will be quiet in front of them.