The most destructive foot-and-mouse disease (FMD) outbreak in Korea occurred in November 2010. Various studies have quantified the economic impact of culling affected animals, mostly swine, from the event by applying different assumptions to the Input-Output (IO) model. The present study takes into account a type of implicit cost, considering the types of effects in the previous literature, as well as costs that have been unaccounted for in prior studies. A seasonal autoregressive model (SARIMA) is estimated employing the number of swine slaughtered leading up to the 2010 FMD outbreak, and forecasts from the model are compared to the actual drop and rebound. The unaccounted implicit cost is estimated to be more than 2 trillion Korean Won (≈ 1.8 billion US dollars), which is a cost Korea must give up or cannot recover. This study serves to strengthen the justification of applying preventive efforts to reduce the likelihood and economic impact of an animal disease outbreak and may be applied in other countries.