Responsible dog owners begin to train their puppies soon after they are adopted. Yet despite training, as dogs mature they often exhibit behaviours that are deemed to be socially unacceptable. Although it is appropriate to reassure the client that a particular behaviour is normal, the behaviour should be addressed if the client is concerned. This chapter deals with evaluation of the patient, treatment, prognosis, follow-up for management problems; problems of obedience, problems of reactivity, problems of self-regulation.