The transplantation of organs, tissues and cells from animals into humans is poised at the threshold of a new and disturbing era. Transplanting animal parts into people, known as "xenotransplantation" (XT) has been limited largely to implanting pig valves into people's hearts; occasional attempts to transplant animal organs into people have grabbed headlines but proved unsuccessful. But the brave new world of XT, still in the experimental phase, involves raising genetically engineered animals, and killing them for their organs. If this practice ever becomes a routine clinical procedure, tens of thousands of animals would likely suffer this fate.
The technical hurdles to whole organ XT remain formidable, if not insurmountable. Nonetheless, activities in this field are moving forward worldwide without close evaluation of the serious ethical, social, and public health implications.
The Humane Society of the United States recognizes that the current demand for transplantable organs exceeds the available supply, that organs from animals are being considered as a means to help bridge this gap, and that humans already raise and kill many species of animals for food. However, The HSUS is concerned that XT represents a short-sighted "fix" that not only exploits animals, but ultimately may prove dangerous to human health.
Before XT ever becomes a routine procedure, society should address the following risk scenarios:
Inadvertently transplanting microorganisms (some of which may be unknown at this time or cannot be "screened out") that thrive in the safe haven of an immunocompromised patient, not only harming the recipient but raising major public health concerns.
Transplanting animal organs that do not provide a long-term solution to organ failure.
In addition to concerns with human health, there are concerns about the welfare of animals used in research related to whole organ transplants, such as the transplant of pig organs into nonhuman primates. These transplant attempts are typically unsuccessful and result in severe pain, distress and suffering of the animals. The conditions in which these pigs are kept are also highly questionable. Concerns over disease have meant they are often kept isolated and in barren conditions, which is completely inappropriate for such highly social and active animals.
There are several other options that, collectively, provide an alternative to XT, obviating the need to use animals in this type of research. These include:
Augmenting efforts to encourage people to donate their organs.
Increasing research efforts on artificial organs and organ-repair techniques.
Encouraging exploration of "presumed consent" laws that presume organ donation unless the person or his/her relatives declare otherwise.
Enhancing efforts to encourage people to adopt healthier lifestyles and diets.
If XT ever becomes routine, despite the availability of these alternatives and the daunting technical hurdles that remain, then the ready availability of animal organs is likely to discourage donation of human organs. A drop in the supply of human organs, which will always remain medically superior to animal organs for transplantation, would hurt patients who do not want animal organs for medical, ethical, religious, or other reasons.
In light of the above, The HSUS believes that XT should not be pursued as a solution to the problem of organ failure and alternatives should be given a high priority.
