Dogs with behavioral problems This study was made to investigate if there was a problem in today’s society regarding dogs showing for example excessive aggression and/or anxiety. The main questions in this study was "is there a problem today" and "if there is a problem, what can we do to prevent it". To investigate these questions interviews were made with six different professions concerning the dog domain. The result of the study shows that three of the interviewed considered it to be a problem, one did not have an opinion on the matter and two choose not to call it a dog related problem because it mostly depends on the owner. Today about 20 – 25 % of the euthanasia’s in Denmark depends on aggressions or anxiety problems. It is the second most common reason for euthanasia. In Sweden 27 dogs were taken into custody during 2010, by the police in Stockholm, when they were considered dangerous to the society because of their aggression and anxiety problems. To prevent the problems from occurring we need to control the breeding more extensively and to be more careful selecting animals on which we choose to breed. Socialization is also an important factor to prevent aggression. Extensive socialization at an early age prevents aggressive behavior towards humans and also other animals. Anders Hallgren, a dog physiologist in Sweden estimates that about 75 % of the dogs that are sent to him for training can be well again.