Zoonotic Disease And Animal Welfare In The U.S.

Animals Industries, Consumption, And Disease

The U.S. produces over 10 billion land animals each year for human consumption and imports more farmed animals annually (over 22 million) than any other country. At present, however, there is no universal disease testing of farmed animals in the U.S., whether domestic or imported. And while the U.S. is also the world’s number-one importer of wild animals (over 200 million per year), many of these wild animals enter the country without disease testing or any kind of physical inspection. 

These facts are particularly poignant on this side of COVID-19 — a pandemic with a death toll just under 7 million at the time of writing, and which is unwise to think of as a one-time disaster. In fact, disease experts worry that it could be dwarfed by future zoonotic pandemics, particularly those caused by influenza viruses, such as the ongoing avian flu (H5N1). H5N1 has not yet spread among humans, but it is being detected among other mammals in increasing numbers. Since non-human mammals are closer genetically to humans than birds are to humans, this may mean the virus is inching closer to infecting humans. Research performed at Stanford University suggests that an H5N1 outbreak could cause as many as a billion human deaths. 

These facts are just a few of the many troubling observations about animal industries, consumption, and disease risk in the United States. Together with our colleagues at NYU’s Center for Environmental and Animal Protection and Harvard Law’s Brooks McCormick Jr. Animal Law & Policy Program, we explored some of these concerns in a report on 36 major American animal industries, from factory farming to the trade in exotic companion animals. In our report, we analyze the threat each industry contributes to zoonotic disease risk, and in turn, how it threatens all of us. The report serves as a helpful resource for advocates and policymakers who wish to improve both human and animal health and welfare.

The Story Behind Our Report

We began this work in 2020, when COVID-19 emerged as a pandemic. At that time, there were respected scientists and policymakers in the U.S. and elsewhere calling for the closure of live animal or “wet markets” around the world, especially in China. A live animal market in Wuhan remains the contested and suspected site of the initial transference of the SARS-CoV-2 virus to humans. Live animal markets are indeed crucial sites for detecting zoonotic disease and preventing pandemics, but calling for the closure of all animal markets, or for closures only in certain geographic regions, meant to us that the law and policy dialogue was not yet engaging the issue of live animal markets effectively. 

Initially, there were five questions driving our research, which we have now investigated across 15 countries. They were as follows:

1. Explore the international landscape of live animal markets: First, we understood that while the policy focus was on markets in China, live markets exist all over the world, including the U.S., Central and South America, and in Africa and Europe. Given the ability for viruses to spread widely from anywhere they originate, a comprehensive approach to live animal markets must be international to be effective. 
2. Clarify the terms and definitions related to live animal markets: Second, it was clear that no one really understood what was meant when referring to “wet markets” and “live animal markets,” and the term “wildlife” was being used without differentiating between commercially-bred or “farmed” wild animals and animals caught in the wild in their native habitats. 
3. Understand the context and role of live animal markets: Third, policy conversations focusing on banning or shutting down live markets disregarded the complex socioeconomic reasons they exist, and the roles they serve — factors that must be understood and addressed in any regulatory response. Who supplies the animals? Who are the customers? What economic, cultural, social, or other motivations have led to the supply and demand for these animals in these markets? 
4. Assess the status quo of regulations: Fourth, we wondered what governmental actors at all levels were already doing to regulate or restrict live animal markets. How broad or narrow was the scope of existing efforts? 
5. Investigate the absence of global regulatory action: Finally, we wanted to interrogate why it was so, if indeed it was the case, that most governmental actors worldwide have so far failed to act effectively regarding disease risks among live animal markets.

We began with a narrow focus, defining live animal markets as locations where (like the market in Wuhan) animals are stored alive then slaughtered on site for sale to customers as food. But it quickly became apparent that we needed to broaden our scope — this proved as instructive for us as we believe it should be for policymakers.

While live animal markets are indeed high-risk sites for zoonotic transmission, it is clear they are only part of a tangled web of supply chains moving and mixing many species in poor health and intense confinement within countries and internationally. As such, our investigations came to employ a broader understanding of “live animal markets” to mean almost any place where the consumption and use of animals brings them into contact with humans in such a way that zoonotic disease can spread.  

In this broader and more accurate sense, live animal markets include, for example, slaughterhouses, fur farms, petting zoos, pet stores, circuses, big game hunting, and upland bird farming. Our study of the U.S. is the first portion of the research that we have made public. It details ways in which the U.S.’s widespread, underregulated animal industries could lead to new animal-to-human (zoonotic) pandemics. The fact is, there is no single geographic region or demographic group exclusively responsible for the spread of zoonotic disease.

How U.S. Animal Markets Pose A Disease Risk

We’re surprised by what we’ve found, as much by the sheer scale and diversity of animal use in the U.S. as by the disconnected patchwork of federal, state, and municipal laws governing animal industries. Some are underregulated and others are totally unregulated.  

Across many animal industries in the U.S., economic incentives cause disease risk to be overlooked in favor of revenue. And where self-interest and public interest point in opposite directions, regulation and enforcement are needed to ensure that producers follow best practices. 

The fact is, we are selling and consuming animals and their body parts and products in the absence of such regulation and enforcement. In this environment, misaligned incentives tend to enhance risks to public health — risks that occur across the supply chain, from the places where animals are born to the homes where they are consumed as food or kept as companions. 

Here are some of the dynamics the report details, including risks among farmed animals, hunting and trapping practices, breeding and slaughtering captive-bred animals (e.g., for fur), and more:

U.S. consumers’ use of animals and animal body parts and products — as food, companions, toys, decorations, clothing, medicine, and more — is enormous. So is the risk to humans and other animals from zoonotic disease spillover. This is an issue both domestically and globally: wealth and consumption habits in the U.S. are driving extractive practices in search of animals and animal products across much of the world. Further, these extractive practices drive spillover risk upstream in the supply chain. 

It is clear to us that the U.S. has significant responsibility in generating global disease risks, and it must fundamentally restructure the way that human-animal encounters occur in the country to minimize the risk and harm it poses to all species.

Using Our Research To Inform Advocacy

Like many animal advocates, our mission involves a commitment to analyzing and improving the treatment of animals. So how does an assessment of zoonotic risk across animal markets help to advance this cause? 

Generally, where animal welfare is poor, disease risk is higher. There are many zoonotic risk factors that relate to animal welfare. For example, the intensity of animal confinement, the health of the animals, veterinary care (or lack thereof), how long animals are used in the supply chain, and the methods of transport can all heighten disease risk. Some stress behaviors (such as cannibalism) that can make animals even more vulnerable to potential pathogens are amplified when animals are housed in poor conditions. 

This research, highlighting just how closely human health is connected to animal health, provides animal advocates with additional reasons why we should all care about animals. While it is true that focusing on disease prevention alone is insufficient (there are industry strategies that improve public health without improving animal welfare—indeed, quite the opposite), there is increasing awareness of the interdependence of animal and human health, along with plant and environmental health. 

According to these frameworks, addressing the health of animals is not merely a “means to an end” that ultimately takes a secondary role to protecting human health. Rather, it is profoundly connected with, and just as important as, the health of humans — and it is difficult to conceive of any industry strategy or technology that could meaningfully undermine this fundamental truth. 

This interconnected framework is referred to as “One Health,” and it’s being embraced by the WHO, the CDC, UNICEF, and even the current White House administration. Despite fair criticisms, the concept can help us understand and address many global problems, including pandemic prevention. A One Health approach emphasizes our interdependence with animals, plants, and the environment, and it suggests collaboration as a way to improve our collective health. Sharing knowledge and using a common language are important ways that organizations, governments, and individuals can help prevent zoonotic diseases that threaten both human and animal health. 

It is in this spirit that we encourage you to review the report and identify the kinds of markets that are within your mission, and even those you encounter in your daily lives, including runs to a grocery store or a summer trip to a state or county fair. The fact is, even the most fringe of these animal markets — coyote urine farming or camel milk production, for example — makes humans and animals vulnerable to myriad zoonotic diseases. To disregard the welfare of any creature puts everyone at risk.