Bioethics Forum Essay

Involuntary Donation: Animal Welfare and Xenotransplantation

The realized promise of xenotransplantation seems to be quickly approaching, following the medical breakthrough of a pig kidney functioning for a record two months in a deceased human body. This milestone has received overwhelmingly positive media attention despite the complexity of the technical and ethical hurdles to overcome. Ethicists, physicians, and transplantation specialists have shared their apprehensions about the risks of implanting animal-grown organs into humans, including zoonotic diseases and organ rejection, which occurred in the latest attempts at pig-to-human heart transplants. However, conspicuously absent from these discussions is a major stakeholder: the animals.

Ethical questions about how we are using animals–let alone questions of whether we should use them–to create organs to transplant into humans have, unsurprisingly, been overshadowed by concerns over human research subjects and organ recipient protections. If mentioned at all in medical and bioethics literature and in the media, animal considerations have been relegated to a brief acknowledgment. Bioethicists have a duty to fully assess the ethical consequences of novel health care interventions on both those who benefit and those who are harmed. Sentient nonhuman animals are an intrinsic part of that moral consideration.

There are three crucial points to consider about the welfare of nonhuman animals used for xenotransplantation. The first point concerns harm done to the animals by the process used to create the pigs and grow the organs. The second concerns gaps in animal welfare oversight. The third is the misconception that pigs are the only animals used in the research; xenotransplantation research has required hundreds of nonhuman primates, too.

Creating organs in pigs that can be used by human bodies is technologically complex and currently inefficient and costly. Different companies use distinct, proprietary techniques. The process usually begins with a collection of pig ovaries, typically sourced from slaughterhouses, which are used to create genetically engineered embryos. The embryos have alterations made in certain genes, have human genes inserted, or have both changes. The genetic alterations are done for a variety of reasons, including preventing organs from growing too big for human use, reducing the chance of zoonotic disease transmission, and minimizing the risk of organ rejection.

The genetically engineered embryos are then cloned to produce exact copies and are implanted into surrogate sows for eventual surgical births. The donor pigs are raised separately from their mothers in a highly sanitized indoor environment. While these conditions preserve the pigs’ status as disease-free, they do this at the expense of the animals’ welfare and quality of life. Compounding animal welfare concerns is the inefficiency of the process. It takes many surgical and medical procedures on many sows to produce one viable pig for organ procurement. Each donor pig must endure a lifelong schedule of invasive procedures and monitoring until it is killed and its organs are harvested for transplantation.

The second point concerns animal welfare regulations. Pig-to-human xenotransplantation research projects are huge endeavors, involving international partners and multiple funding sources. In the United States, unlike in other regions such as the United Kingdom and the European Union, oversight of animal research is decentralized, handled within each institution, and differs based on the funding source. When projects include international partners and a mix of private and public funders and sites, it can be unclear what animal welfare regulations are mandated. Standards of care may also differ at each research site. Given the problematic history of xenotransplant animal welfare violations, one might conclude that researchers have an incentive to produce pigs for xenotransplantation in the U.S. to circumvent more stringent welfare standards elsewhere. Indeed, that is precisely what was alleged in the year 2000 when Novartis moved its xenotransplant research subsidiary from the U.K. to the U.S.

Animal welfare concerns in xenotransplantation are not limited to pigs. Pig organs must be transplanted into nonhuman primates before they can be transplanted into humans, according to Food and Drug Administration research requirements. These preclinical trials are fraught with welfare concerns, as primates undergo several invasive medical treatments and surgical procedures to implant pig organs, frequently leading to premature death. While the involvement of pigs in xenotransplantation is obvious, most people probably don’t realize that nonhuman primates are also involved. But the public should know. Data on people’s attitudes toward the use of nonhuman primates in xenotransplantation is needed in the literature for consideration by bioethicists and others concerned with the animal welfare issues it raises.

A powerful, yet deeply problematic analogy that has been used to undermine concerns of animal welfare in xenotransplantation draws a comparison between industrial pork production and xenotransplantation. Namely, if pigs are already bred for human food consumption, it should be permissible to breed them for transplantable organs. But this argument is flawed. Industrial pork production is ethically fraught for both the animals and the laborers in the industry. There are dangers in using this practice as the standard against which to compare the use of pigs in xenotransplantation when the standard itself is ethically questionable. This line of thinking perpetuates the lack of moral consideration of the use of livestock animals in different contexts, something that deserves careful deliberation.

If xenotransplantation proves successful in clinical trials, the use of nonhuman animals to produce organs suitable for transplanting into humans is both inevitable and essential. But the simple fact that xenotransplantation helps people is not reason enough to disregard animal welfare concerns. We must consider how this emerging medical treatment affects the nonhuman animals involved.

The first step is for private entities that produce and test animals for xenotransplantation to be transparent about how the animals are treated and which animal welfare oversight standards are used. Claiming the need to protect proprietary research secrets or intellectual property of the pig creation process is not a justifiable excuse for avoiding transparency. This basic and fundamental information is necessary for bioethicists and others to examine ethical issues that nonhuman animals face in xenotransplantation research methods. Only then can there be well-informed, nuanced deliberation on how to ensure a high standard of animal welfare and regulatory oversight, and how to limit the number of animals used in this novel research. Until there is greater transparency, we will remain where we are now: unaware of the cost to the nonhuman animals that are critical to the success of pig-to-human organ transplants–and at a loss for how to weigh them.

We find ourselves at a crossroads, both hopeful about this emerging medical breakthrough and troubled by its implications for fellow sentient and intelligent beings.

Sana Baban, MBE, is a project manager and research assistant at The Hastings Center. @sana_baban

Ashlin Amano, MBE, is an administrative coordinator in Columbia University’s department of Medical Humanities and Ethics. @ashlin_amano

Lisa Moses, VMD, a veterinarian and animal focused bioethicist, is a faculty member at Harvard Medical School’s Center for Bioethics and a senior advisor to The Hastings Center.