It is a professional doctorate \/ first professional degree ( qualifying degree ) in some countries , including the United States and Canada . Students need to have completed 90 to 120 credit hours of university level work ( see second entry degree ) and in most cases should already have a Bachelors Degree . It is a professional doctorate \/ first professional degree ( qualifying degree ) in some countries , including the United States and Canada , although training is entered after obtaining from 90 to 120 credit hours of university level work ( see second entry degree ) and in most cases after having obtained a Bachelors Degree .