History of World Blood Donor Day:
The first transfusions were done using poorly understood science and resulted in some rather tragic results for the patients. Richard lower was the first one to examine animals and blood circulation and finding ways to stop blood clotting.
While he was of course only working with animals, he managed to drain the blood off of a medium-sized dog and then transfuse the blood of a large mastiff into the smaller animal. Both dogs recovered with no appreciable ill effects.