With its quarterly profits dwindling, McDonald’s half-century reign as the world’s most dominant fast-food force may be near an end. In February alone, for example, US sales dropped 4 percent and global sales fell 1.7 percent. McDonald’s is exploring ways to reverse the negative trend, and Paul Shapiro, Vice President of The Humane Society of the United States, suggests a solution: add vegan options to the menu. “So many of McDonald’s competitors are serving plant-based entrées, and McDonald’s is lagging behind,” Shapiro told ABC News. So with Denny’s, White Castle, and Johnny Rockets all serving veggie burgers, McDonald’s may be next in line.