heterogeneous organ transplantation
A transplant procedure that transplants an organ or tissue taken from an animal. One of the most common examples is the use of pig hearts that have been spliced with human DNA. With the development of new transplant techniques, the danger of the animal passing on an infection to the recipient has been lowered; however, they have come into use more as a bridge-to-transplant than a permanent replacement. Many organizations and industries oppose such transplants on ethical grounds, and they are not officially permitted or supported by the government.
There have been numerous documented cases of this type of transplant throughout history, such as the transplantation of baboon livers into humans at the end of the 20th century.