For more than 40 years, Bulldog Contractors in Jefferson, Texas, has relied on a simple formula for success: Adapt to changing market conditions, invest in advanced technologies, provide great customer service and build a diversified business that’s a one-stop shop for customers.The company’s transition decades ago from a residential-remodeling general contractor to a plumbing firm reflects its ability to change with the times. Owner Carl Keller, who established the East Texas company in 1978, made the switch to survive, not by choice. But it turned out to be a fortuitous move for both Keller, who’s semiretired and still owns the
