I had a member of PedsOnline ask me just now about the myth of "Black Blood" ... and why so many ooohh and aaahh about seeing "that black blood" in the pit (as somehow they think this indicates an elevated state of damage to the other dog).

The reality is, "black blood" only means that a VEIN has been hit, not an ARTERY.

  • In simplest terms, veins bring blood back from the extremities to the heart;
  • By contrast, arteries bring blood from the heart to the extremities.


  • This means that "black blood" = blood coming back to the heart that is not oxygenated
  • Whereas "red blood" = blood coming from the heart/lungs TO the vital organs/extremities that is now fully-oxygenated.


While no form of blood loss is good news for your dog, ultimately black blood (a vein cut) is actually the LESS dangerous blood loss, as the blood has already serviced the limbs/organs with oxygen.

Therefore, in exact opposition to the myth, the reality is BRIGHT RED blood loss (an artery cut) is MORE dangerous, because the fully-oxygenated blood supply is now lost or at least impaired in that area ...

Jack