Lisa DeMuro, owner of Walkin’ the Dog in Bar Harbor, is in the business of pets — and business is good.

“The pet industry is huge and it just gets bigger every year,” said DeMuro. “It’s one of the few that are out there in this economy that aren’t floundering.”

Since opening her doors in 2008, DeMuro said sales for her store have increased each season and the 2011 summer tourist season has been the best to …