Mega-cities in South America are well known for their favelas. But in contrast to Sao Paulo and Rio de Janeiro, these shacks in the southern Brazil town of Caxias do Sul are not occupied by people. Rather, the "doggy favela," as locals call it, provides a home to the some 1,600 abandoned canines and 200 stray cats cared for by the NGO Sociedade Amiga dos Animais.