In the Blood

This is an article I wrote for The Chronicle of the Horse at least 20 years ago, though I’m not sure what issue it was in. At the time, I was working at a site administered by the Minnesota Historical Society, where the bloodletting of its human occupants was the norm. I wondered if it was used to treat animals as well, so I researched the subject. This is the results.


An 18th century book illustration showing a man preparing to bloodlet a grey horse.
Bloodletting a horse from an 18th century Hindi text
Credit: Wellcome Library, London.

Picture poking a hole in your horse’s neck to treat his ills. Imagine his blood coursing down his shoulder, down his foreleg, onto the ground. Lots of it, a gallon or two or more, perhaps until his knees buckle and he faints. And imagine repeating this gory process again and again, sometimes for days, until he gets better–or dies.

Insanity? Few twentieth century folks would disagree, yet as a medical procedure for man and beast, bloodletting, also called bleeding and venesection, persisted for a long, long time.

Hippocrates, writing and practicing medicine in the fourth century B.C.E., authored a comprehensive treatise on bloodletting. Building upon Hippocrates’ notes, the Greek physician Galan was first to stipulate exactly how much blood should be drained (for a human, from seven or eight ounces to as much as a pound and a half; in certain cases until the patient fainted).

And throughout the ‘civilized’ western world, for century upon century, the grisly practice persisted. Why? Because folks believed it worked. Continue reading “In the Blood”