The most frequent species are cattle and sheep (see Figure 1a ). There are less than 3% farms with pigs only and only 10 farms with just pigs were diagnosed as IPs in 2001 (less than 1% of all the IPs). This indicates a-priori that pigs contributed far less to the 2001 outbreak than many other FMD outbreaks (despite their high levels of shedding [1, 17] ), and we therefore decided to discard pigs-only farms from the current study to simplify the analysis. The Sensitivity Analysis section shows that this simplification does not significantly affect estimates of other epidemiological parameters. We discarded another three IPs due to missing information or possible mistakes regarding their location or number of animals, leaving a total of 2013 IPs in our analysed dataset.