Under normal circumstances, you are not allowed to work under a Visitor Visa Status and will require a Work Permit. You may not need a work permit if you fall into one of the following categories:
Athletes and coaches
Aviation accident or incident investigators
Business visitors
Civil aviation inspectors
Clergy
Convention organizers
Crew members
Emergency service providers
Examiners and evaluators
Expert witnesses or investigators
Family members of foreign representatives
Foreign government officers
Foreign representatives
Health-care students
Judges, referees and similar officials
Military personnel
News reporters, film and media crews
Performing artists
Public speakers
Students working on campus
Business visitors
Business visitors do not need a work permit. Even with these, there are a few regulations. You can extend your visit visa if all of the original conditions under which you gained entry into Canada remain unchanged. It is only advisable to extend once.