A dog eagerly awaits adoption in an animal shelter. iStockphoto.com hide caption toggle caption iStockphoto.com The Two-Way Oh, Poop! Animal Shelter May Still Need More Newspapers February 7, 2013 San Francisco's library system responded to the city shelter's need for newspapers with donations of its used copies. But dogs are "poop machines," as a shelter spokesman says. So the problem may not be quite solved.