I am writing about a blood magic cult, and they drink/paint with collected blood to preform rituals and bursts of magic. Most of their supply is garnered through the use of human cattle, but in a pinch blood of other animals can give some power (but the power is greatly reduced). The story takes place in a mythical setting, but I would like to stick to creatures found on Earth.

I know primates have similar blood, but what about other kinds of animals? It would help my story to have a list of non-primate animals that have blood similar to human blood, and figured this would be the place to ask. The best answer would have a few animals with very similar blood, a few animals with extremely different blood, and a short explanation of what makes it so.

  • $\begingroup$ google.com/… $\endgroup$ – Morris The Cat May 15 at 15:56
  • $\begingroup$ @MorrisTheCat I edited my question to be more specific. $\endgroup$ – Alex May 15 at 16:00
  • $\begingroup$ Attention VTCers! Real-world questions are on-topic so long as sufficient context is provided, which I believe has happened here. The question may be downvotable for insufficient research (sorry Alex, but Morris' point with his link comment was that basic research wasn't hard), but I don't think this should be closed. $\endgroup$ – JBH May 15 at 16:24
  • $\begingroup$ I didn't edit out the term "human cattle." Do you mean actual humans used as cattle? or do you mean cows that are domesticated by humans? If the latter, wouldn't you want blood similar to cows? That's what the cult is used to working with after all. Please clarify in the question itself but adding a comment that it's been done, or why you're choosing not to do it, would be helpful (so we notice). $\endgroup$ – Cyn May 15 at 16:51
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    $\begingroup$ All vertebrates have similar blood (except those which don't, but those are specific exceptions due to special circumstances). Quick, can you tell off the top of your head what are the differences between salmon blood and human blood? Or between chicken blood and human blood? Or between pig blood and human blood? And even more so when considered as food, not as blood; when considered as food almost any kind of vertebrate blood (except exceptions due to specific adaptions) is pretty much equivalent -- too much salt, much too much iron, some sugar, little protein, nowhere near enough fat. $\endgroup$ – AlexP May 15 at 16:53

In general, blood is not under significant selective pressure, and when it is - e.g. elongated erythrocytes of camels - it's usually confined to the odd species rather than whole higher taxa. As such, genetic drift should be the main driver of blood changing over generations.

Therefore, the further phylogenetically we go from Primates, the less and less similar the blood will be. In order of similarity, a list would by this reasoning go like this:

  • Colugos
  • Tree shrews
  • Rodents, rabbits, hares & pikas
  • Ungulates, carnivores, whales, bats, pangolins and shrews & kin
  • Anteaters, sloths, armadillos

So, colugos would be the absolute best non-primates for blood. They;re only found in Southeast Asia, though, as are tree shrews, so perhaps rodents would be the best bet - they're cosmopolitan, and wherever they're found they're really damn common.


I recently read online a somewhat improbable theory that the first humans were hybrids,the result of intercourse between chimpanzees and wild pigs. A rather dubious theory, but no doubt suggested by the many biological similarities between humans and pigs.


As a matter of fact, pig blood is similar enough to human blood that there is serious medical interest in ending blood shortages by using pig blood - possibly genetically modified pig blood - for transfusions. So it is possible that pig blood might someday be used for medical transfusions, which makes it seem like pig blood is a rather good candidate for nonhuman blood that is most similar to human.




  • $\begingroup$ That hypothesis is bollocks, I'm afraid. Eugene McCarthy is a laughing stock in biology, almost a meme at this stage. $\endgroup$ – SealBoi May 15 at 17:19
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    $\begingroup$ @SealBoi But the OP didn't ask about that hypothesis, but about animals with blood similar to humans, and apparently pig's blood is a good choice for non primate blood very similar to human blood. $\endgroup$ – M. A. Golding May 16 at 16:56

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