What was the first animal used in a blood transfusion according to the history provided?

The first animal used in a blood transfusion was indeed a lamb. Historical records indicate that early transfusions were performed on various animals, including lambs, as part of biomedical research and experimental practices. In the context of exploring blood transfusion techniques, lambs were among the first subjects due to their size and the ease with which blood could be drawn and administered. This early experimentation laid the groundwork for further understanding of transfusion compatibility and techniques.