Unadjusted Kaplan-Meier survival curves for FMD cases and non-cases related to culling. Animals were included in the analysis if present on the farm during the outbreak period (31st August-28th September 2012) and were followed for 12 months after the commencement of the outbreak. Culling was defined as exiting the herd due to any disease, death or low production. Log-rank test for equality of survivor function, P = 0.0036. The Y-axis represents the cumulative probability of not being culled.