Fig. 3From: Influence of border disease virus (BDV) on serological surveillance within the bovine virus diarrhea (BVD) eradication program in SwitzerlandFarms with BDV-positive sera and case and control farms in Switzerland and the Principality of Liechtenstein (LI). The location of farms with BDV-positive sera (circles) including the definitive case farms (triangle) and the control farms (squares) are presented. The number of BDV-specific sera from one to four is displayed by a color gradient from yellow to red as indicated in the figureBack to article page