The current bird flu outbreak in Massachusetts is the largest the state has ever seen. Here's why officials believe it has become so widespread and what residents should do to protect themselves (and their pets).

Bird flu appears to be widespread in Massachusetts, state health and environmental officials said Wednesday. The Division of Fisheries and Wildlife (MassWildlife), the Massachusetts Department of Agricultural Resources (MDAR) and the Massachusetts Department of Public Health (DPH) said bird flu -- also known as highly pathogenic avian influenza (HPAI) -- is suspected to be the cause of death in cases of both wild and domestic birds in several Massachusetts municipalities.