Trapping as an alternative method of eradicating classical swine fever in a wild boar population in Bulgaria

Between August and November 2009, eight cases of classical swine fever (CSF) occurred in young wild boar in a 25-km2 oak forest 3 km south of the river Danube in the north-eastern part of Bulgaria. The wild boar population within the affected area was estimated to be 156 animals, or approximately six boar per km2. To control and eradicate the disease, and in addition to vaccination and hunting, trapping was used to reduce the boar population to below two animals per km2. In total, 124 wild boar were removed from the infected area within three months. Of these, 119 were trapped. In this paper, the authors present trapping as a successful tool to eradicate CSF from an area where hunting and vaccination alone might not be sufficient. Up to seven wild boar could be trapped in a single trap. Furthermore, the spread of CSF virus to the local domestic pig population and to wild boar in neighbouring areas was prevented. By decreasing the wild boar population to fewer than two animals per km2 , it was assumed that the virus would no longer circulate and the disease would fade out. In fact, no further CSF cases were diagnosed afterwards. Under Bulgarian and similar conditions, trapping seems to be a more reliable method than hunting for reducing a wild boar population within a short period of time. Furthermore, trapping may be used alone or in combination with hunting, depending on the situation.