What is the oath taken by doctors?

Technically, yes. Only they will swear under different types of oath, such as modified Hippocratic Oath, The Physician's Oath, Declaration of Geneva, Oath of Maimonides, Osteopathic Oath, and many others. Surveys states that some countries have its own oath that doctors will have to sign. Most of the oaths was modified from original Hippocratic Oath.