Working dogs, pet or employee?

Some lines of work such as law enforcement and search and rescue with fire departments have long since relied upon specialized dogs in their line of work. Naming a few: german shepherds with police, Dalmatians with firefighters, golden retrievers and labs as medical alert service dogs. What other breeds can you name as modern working dogs? In urban/suburban environments? In rural environments? Along coasts (such as Great Lakes)

As a new business owner, who personally travels most places with my American Brittany (a spaniel line breed for upland hunting) I have an internal debate and question for others in the environmental community. Can or should a pet be an employee of a small business, or should they always remain a pet? Should they be certified as a service dog ? If so, by state or federal standards?

Can said dog travel into work sites? What are the limitations to dogs as working animals?