The Dobermann, (/ˈdoʊbərmən/; German pronunciation: ) or Doberman Pinscher in the United States and Canada, is a medium-large breed of domestic dog that was originally developed around 1890 by Karl Friedrich Louis Dobermann, a tax collector from Germany. The Doberman Pinscher has been ranked amongst the most intelligent dog breeds in experimental studies and expert evaluations. Psychologist Stanley Coren ranks the Dobermann as the 5th most intelligent dog in the category of obedience command training, based on the selective surveys answered by experienced trainers (as documented in his book The Intelligence of Dogs). The Dobermann's lifespan is about 10–13 years on average. The breed is prone to a number of health concerns. Common serious health problems include dilated cardiomyopathy (DCM), The Dobermann became very popular over a short period of time. Dobermanns started to become popular when they were used in World War II as guard dogs.