Xenotransfusion

The first recorded blood transfusion was performed between two dogs in 1665. Carotid artery blood from the lamb was introduced to a vein in the patient's inner elbow, and the procedure ultimately resulted in a successful recovery. Denis and Emmerez performed multiple xenotransfusions together. On June 24, 1667, the duo performed a transfusion on a young Swedish nobleman. When they arrived, the patient had already lost his ability to speak and was practically unconscious. Shortly after the transfusion began, the patient was able to speak again. His health was improving until his condition grew progressively worse. A second transfusion took place, but it was unsuccessful, and the patient died. Richard Lower, an English physician, performed a similar procedure on November 23, 1667. He successfully transfused the blood of a lamb to a 22-year-old man. In both cases, the whole blood of the lamb was directly introduced into the vein of the patient. The direct introduction of blood was due to a lack of knowledge in preventative blood coagulation techniques at the time. After several xenotransfusion procedures, some successful some not, the French Parliament prohibited the practice of these transfusions in 1670. The English Parliament, as well as the Pope, followed suit and prohibited the procedures shortly after. ==Ethical arguments involving the pig for xenotransfusion==

Xenotransfusion uses non-human animals to aid in the shortage of blood for blood transfusion in humans. Some scientists preliminarily favor Sus scrofa domesticus (pigs) as a source of blood after having tested many different animals in order to find the best candidate for a blood donation. Pig red blood cells (pRBCs) show many characteristics similar to that of a human, including RBC diameters (pig 6 μm; human 7.2 μm), RBC counts (pig 5.7 to 6.9 million/ll; human 4.2 to 6.2 million/ll), and RBC average lifespan (human 86 days; pig 120 days). Current evidence shows that pRBCs will function normally in humans due to the relation between porcine blood groups and human ABO group system. In addition, it is possible to produce pigs with type O blood and to genetically modify pigs to make their blood more compatible with humans. Sus scrofa domesticus's blood may be used to save lives and to increase blood quantity. The organism is kept alive and no serious harm is involved, similar to how blood is removed from humans. One article examining the ethics of xenotransfusion notes that only 10% of the animal's blood volume is used each time; therefore, it may be considered ethically acceptable to raise pigs for periodical blood collection as it does not damage the health of the animal. Likewise, using pRBCs on humans would not cause severe harm to human health. ==Veterinary xenotransfusion==

Transfusion of canine blood into domestic cats was performed historically and continues to be performed in some countries. Xenotransfusions have been performed on birds, though the procedure is only done to stabilize a bird in shock, due to rejection by the recipient bird's antibodies. Xenotransfusion of bovine whole blood into domestic goats has been preliminarily investigated as a potential option for anemic goats. When comparing caprine-recipient bovine-donor cross matching a study found 11/15 caprine-bovine combinations compatible on both major and minor cross matching. ==References==