Final answer:
The correct term for RBCs arranged like stacks of coins on a peripheral blood smear is Rouleaux, which can be a normal finding in certain species or an artifact.
Step-by-step explanation:
RBCs that are arranged like stacks of coins on a peripheral blood smear and may be either an artifact or normal in species such as cats and horses are known as Rouleaux. This term refers to the appearance of red blood cells when they form aggregations that resemble stacks of coins. Other options like Agglutination, Poikilocytes, and Target cells represent different erythrocyte morphologies or reactions. Agglutination refers to the visible clumping of red blood cells that can be caused by some viruses, bacteria, and certain diseases where antibodies bind to self-red blood cells. Poikilocytes indicate irregularly shaped red blood cells, and Target cells are red blood cells with a characteristic bullseye appearance.