Question: What are the requirements to become a licensed doctor?
About the article "Medicine", section "Legal controls".

Candidate passages:
Kathy McKeever, Chief of the Bureau of Naturopathic Medicine, described licensing as "that a naturopathic doctor has met the minimum professional standards and passed required examinations.
To maintain their license, doctors must also meet ongoing educational requirements that help them stay current with professional practices.
"In California, only licensed professionals can legally call themselves "naturopathic doctor," "licensed naturopathic doctor" or "doctor of naturopathic medicine."
Licensed naturopathic doctors can prescribe drugs using standardized procedures or protocols established jointly with a supervising licensed physician and surgeon.
However, naturopathic doctors are not "medical doctors," "M.D.s," "D.O.s," or "physicians."
The education of social workers begins with a Bachelor's degree (BA, BSc, BSSW, BSW, etc.)
or diploma in Social Work.
Some countries offer Postgraduate degrees in Social Work, such as a master's degree (MSW, MSS, MA, MSc, MRes, MPhil.)
or doctoral studies (PhD and DSW (Doctor of Social Work)).
Increasingly, graduates of social work programs pursue post-masters and post-doctoral study, including training in psychotherapy.
In the United States, social work undergraduate and master's programs are accredited by the Council on Social Work Education.
A CSWE-accredited degree is required for one to become a state-licensed social worker.
A number of countries and jurisdictions requires registration or licensure of people working as social workers, and there are mandated qualifications.
In other places, a professional association sets academic requirements for admission to the profession.
The success of these professional bodies' efforts is demonstrated in that these same requirements are recognized by employers as necessary for employment. 
North America.
In Canada, in order to obtain their professional designation, doctor of optometry degree, optometrists typically must complete minimum three years undergraduate education, and a four or five year university program in optometry accredited by the Accreditation Council on Optometric Education.
There are two schools of optometry located in Canada and 20 in the United States that are accredited and recognized in Canada.
The two Canadian schools of optometry accredited are at the University of Waterloo and at Université de Montreal.
Upon completion of their optometry education, they are also required to satisty the provincial requirements of the province or territory they are intended to practice.
These requirements include a national examination administered by the Canadian Examiners in Optometry, and licensure by the provincial or territorial governing body.
Optometrists in Canada are licensed to prescribe topical and oral medications, however, the exact medications that they are licensed to prescribe varies province by province. 
Banks are required to be issued with a bank license by the regulator in order to carry on business as a bank, and the regulator supervises licensed banks for compliance with the requirements and responds to breaches of the requirements through obtaining undertakings, giving directions, imposing penalties or revoking the bank's license. 
The U.S Department of Agriculture (USDA) requires businesses that either buy or sell warmblooded animals, exhibit them to the public, transport them commercially, or use them in teaching or experiments, must be licensed or registered.
Failure to become licensed or registered is a punishable violation of the Animal Welfare Act.
Depending on the basis of the business, the Animal and Plant Health Inspection services (APHIS) determines whether the business should be licensed, registered, or both.
Business owners are responsible for knowing about registration and licensing requirements.