We have a U.S. worker who will be providing training to the Canadian government for 5 days or less. Do they need to have a special visa to do so? We do have an office in Toronto. If so, how long does it take to be issued?

The nature of the training would determine the requirement for a work permit. Depending on the nature of the assignment, the processing of an application for either business visitor admission or a work permit can take anywhere between 1 day and several weeks.