Spatial distribution of free-of-charge pathology submissions to the California Animal Health and Food Safety laboratories during the exotic Newcastle outbreak in 2002-2003.

After the 1971-1973 outbreak of exotic Newcastle disease (END) in California, a free-of-charge diagnostic submission program was created for backyard poultry flocks. This program was implemented to improve disease surveillance in small poultry flocks. The aim of this study was to evaluate the spatial distribution of free-of-charge pathology submissions to the California Animal Health and Food Safety laboratories during the END outbreak in 2002-2003.