ELI5: Explain Like I'm 5

Blood type (non-human)

Blood type (non-human) is a way of categorizing certain animals based on the type of proteins found on the surface of their red blood cells. Different animals have different proteins on the surface of their red blood cells so this helps us tell animals apart. For example, cats have a protein called A on their red blood cells, whereas dogs have a protein called B on theirs.