Most of the outbreaks reported in Thailand concerned backyard poultry (Chantong and Kaneene, 2011). Backyard poultry production was also implicated in the transmission of HPAI H5N1 in the beginning of several epidemics in other countries (Alders et al., 2013). A better understanding of the disease dynamics of the backyard poultry sector will aid in controlling the spread and persistence of HPAI H5N1.