David Waltner-Toews is a veterinarian, as well as a specialist in the epidemiology of food- and water-borne diseases and zoonoses, infectious diseases transferred from animals to humans. He has written books about chickens and travelled the world to combat bird flu. So when his wife gives him a box of chicks on his birthday to begin raising his own backyard chickens Waltner-Toews is not all that worried about what could go wrong. Soon he finds...