Global animal trade has transformed zoonotic risk and the economics of outbreak control

The global movement of animals has expanded dramatically, reshaping not only livestock production but also the pathways through which pathogens move between wildlife, domestic animals and people. An anthropological analysis from the University of Helsinki argues that modern animal production has created a “bioeconomy of zoonoses”: animals, their genetic material and even the risks generated by disease now form part of interconnected economic systems.

Published in Cultural Anthropology, Sarah Green’s analysis places zoonotic disease in the context of centuries of animal trade, breeding and domestication. What has changed most, she argues, is not that animals and pathogens move, but the scale, speed and economic concentration of those movements.

Around two billion live animals cross borders each year

The paper cites estimates that the number of live animals transported internationally has quadrupled over the past 50 years to around two billion animals annually. At the same time, livestock genetics have become increasingly standardised through international breeding, artificial insemination and specialised production systems.

Modern cattle, pigs and poultry are frequently bred for highly specific production traits, while local breeds have declined in many regions. This concentration may increase productivity, but it also links distant animal populations through common genetics, trade networks and production practices.

The epidemiological consequence is straightforward: when animals move more frequently and over longer distances, pathogens can move with them.

Industrial livestock systems changed disease control

Green uses foot-and-mouth disease (FMD) as an example. FMD was historically tolerated as an endemic disease in some European livestock systems because most infected animals recover. The emergence of highly interconnected commercial farming and trade fundamentally changed that calculation. In modern livestock economies, an outbreak can interrupt national and international trade almost immediately. As a result, control strategies based on mass culling and rapid eradication can make economic sense even for diseases that are not usually lethal to the affected animals.

The response therefore reflects not only the biological characteristics of the virus, but also the vulnerability of a highly connected production system.

The Danish mink cull illustrates the same logic

The paper also examines Denmark’s decision in 2020 to cull around 15 million farmed mink after SARS-CoV-2 variants emerged in mink populations. Humans had initially infected the mink (a reverse zoonotic event) before concerns arose that new viral variants could return to people. For Green, the episode demonstrates how intensive animal populations can become both biological amplification systems and economic liabilities when an emerging pathogen enters them.

Changing farming systems also reshape wildlife interfaces

The consequences extend beyond trade. Changes in livestock production can alter landscapes and animal contacts. As sheep and goats move from extensive grazing toward indoor systems, for example, abandoned grazing areas may increasingly be used by wild boar, wolves, jackals and other wildlife.

At the same time, agricultural expansion, habitat fragmentation and transport create new interfaces between wildlife, livestock and humans, precisely the environments where spillover and spillback can occur. The paper argues that these interfaces cannot be separated from the economic systems that created them.

Zoonoses have themselves become an economic sector

The most provocative argument is that zoonotic risk has become part of the bioeconomy. For centuries, infectious disease was mainly an obstacle to animal trade and production. Today, surveillance, diagnostics, vaccines, biosecurity technologies and outbreak preparedness have themselves become large areas of investment and commercial activity. In other words, modern economies do not merely move animals and pathogens: they also create markets around detecting, predicting and controlling those pathogen movements.

This perspective does not replace epidemiology. It adds another layer to it. The emergence and control of zoonotic disease depend not only on viruses, hosts and vectors, but also on how animals are bred, traded, transported and valued economically.