Biosecurity practices that prevent disease entry to farms have direct welfare benefits. However, some biosecurity measures themselves carry welfare costs that must be managed.
Disease prevention on farms has significant welfare benefits — preventing outbreaks protects animals from suffering disease. However, the response to confirmed or suspected disease outbreaks can itself cause massive welfare harm: the precautionary slaughter of millions of animals during the 2001 FMD outbreak was one of the largest single welfare events in UK history. Mass culling of animals, many of which are healthy, represents a welfare harm justified by disease control necessity. The welfare-positive approach invests in vaccination development, rapid diagnostic capacity, and targeted control measures that minimise preventive slaughter of healthy animals.