Today in Denmark, residue surveillance is conducted at random. However, if the surveillance is targeted to high-risk finisher pig herds, then the number of samples can be reduced whereby resources can be saved without jeopardizing public health. An analysis of Danish data covering 2.5 years has shown that finisher pig herds with a very high prevalence of chronic pleuritis have a higher risk of residue findings in the surveillance programme. If this is incorporated into the own control, then cost savings of 25% can be obtained. However, as shown in the Danish data there are other reasons for the presence of residues such as miscommunication and insufficient marking of treated animals. Such cases should be prevented through information campaigns addressed to the farmers and their advisors.