They are easy to raise and produce large litters. They don't waste much time being piglets, but grow to full size quickly. This controversial procedure is being touted as a possible solution to the current organ donor shortage. Doctors have already made several attempts at xenotransplantation, using organs and tissue from baboons. However, the animal with the best potential for wide-scale xenotransplantation is the pig.
Pigs are immunologically compatible to humans and their organs are similar in size to human organs.
The Department of Health and Human Services recently issued a revised draft of guidelines on xenotransplantation that, if approved, will open the door to greater experimentation with the procedure. In one corner are the transplant surgeons, who say, 'We're going to do this. There is growing cause for concern. Based on these findings, researchers noted that it will be difficult, if not impossible, to breed virus-free pigs. Endogenous retroviruses usually do not cause illness in the host species.