Aujeszky illness has been one of the biggest health problems in the porcine sector. This situation has provoked that many countries in the European Union have developed different programmes to control and eradicate it, and that countries and regions have been qualified as officially unharmed by the illness. The logical consequence of this situation is the application of additional guarantees for animal movement and the fact that eradication of Aujeszky constitutes one of the essential basis for intercommunity market and international trade.