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The horse has been one of the most important animals throughout human history, and healing horses has had an important place in veterinary and medical literature. Theories about equine physiology and health often mirrored theories about humans, and the literature of both was inherently linked. Bloodletting, astrology, and ancient texts were used by both physicians and veterinarians to heal their patients, and many discoveries, including the circulation of the blood, developed in tandem.


The Hippiatria: Ancient Texts

Medieval and Renaissance veterinary medicine looked to ancient veterinary texts for its inspiration, just as physicians for human healing did. In the case of horses, veterinarians relied on a set of Classical and Byzantine Greek texts called the “Hippiatrica,” which was based strongly on ancient Greek texts by physicians like Hippocrates. The most noted of these veterinary authors was Apsyrtos, a military veterinarian in the service of the Roman Emperor Constantine I.

Title page with large woodcut of horse facing left with uplifted right foot.
Page of Greek text with several headings and subheadings and an illustration initial letter T.
Woodcut illustration of two horses, in upper part of the page is a horse facing left with uplifted front left foot and tail, at bottom a horse facing right with all four feet on the ground.

Early Growth

Physicians and veterinarians alike were interested in fetal development, and their research often went in tandem, sometimes appearing in the same or closely related works. In reverse order from other anatomical study, detailed images of equine fetal development appeared in publication earlier than did those for humans.

Woodcut illustration of a fetal horse attached by umbilical cord to a large complex placenta.
Copperplate engraved illustration of a newborn human baby lying on its back with umbilical cord attached to large placenta.
Woodcut illustrations of two fetal horses, the upper horse still in its placenta, the lower one outside placenta but still in fetal position with umbilical cord exposed.

Health Charts

Disease Man and Disease Horse

A common chart from medieval and Renaissance medical texts is “Disease Man,” wherein the diseases that can affect different parts of the body are laid out schematically around the body. Horse veterinarians adopted this chart, creating a “Disease Horse”; this chart often served as an index to the book, stating the page on which a particular horse disease could be found.

Woodcut chart showing nude male figure facing front surrounded by disease labels linked to body parts.

Woodcut chart showing a horse in the middle of the page with the twelve symbols of the zodiac linked to parts of the horse’s body.
Woodcut chart showing a male figure facing front with the twelve symbols of the zodiac linked over the body parts and labeled with effects.

Astrology and Health

An important ingredient to medieval and Renaissance human healing was Astrology, whereby the influence of the stars on the body was studied and carefully charted. Veterinarians did the same with horses. In these two charts, the signs of the zodiac are associated with different parts of the body: for example, don’t treat the head while Aries is in the sky.

Bloodletting and the Four Humors

Central to early theories of human health was keeping the four humors (blood, bile, black bile, and phlegm) in balance, which involved the practice of bloodletting. Veterinarians followed suit and created bloodletting charts and systems which were similar to those created for human healing.

Woodcut chart showing a man facing forward with torso and chest open to show internal organs 48 lines labeling pointing points on the body for bloodletting.
Copperplate engraving showing a woman, sitting on a bench supported by another woman having her right ankle bled by a surgeon while a woman holds a candle.
Woodcut illustration set in the text showing a horse with cuts releasing blood from its face, neck and hip.

Studying Form

In the mid-1500s, sumptuous anatomical studies of human anatomy began appearing as an explosion of human dissection yielded a new perspective on the human form.

Woodcut anatomical illustration of a standing horse in profile showing exposed musculature in a landscape with stars.
Woodcut anatomical illustration of a man standing and facing left with right arm uplifted, showing exposed musculature, with ruined stonework in the background.

Prompted by this, veterinarians published similar studies of the anatomy of the horse which focused not only on the science of the body, but used a great deal of art and aesthetics to convey its subject matter.

Copperplate engraved illustration of the nervous system of a flayed horse
Woodcut human figure outline arms outstretched showing the branching pattern of the circulatory system.

Reading Bodies

Physiognomy: A Study in Character

Physiognomy was the science of predicting a person’s character and health according to his physical appearance, especially the face and head. This ancient science dated back to Hippocrates in the fifth century BC, and Giambattista della Porta (1535?-1615) popularized it two thousand years later, comparing different human forms to animals. In this image, he shows that noble humans often resemble the noblest of animals, the horse.

Copperplate engraved illustration of a man and a horse in profile, each facing right, with the man wearing a toga.

Copperplate engraved illustration showing the physics of motion of three birds, three fish, and a leaping horse, with comparisons of a squatting man, dog and monkey.

Physiology and the Science of Motion

Physiology, or the science of how the body functions, was studied in tandem by horse veterinarians and physicians, as each tested their hypotheses on patients. Giovanni Alfonso Borelli (1608-1679) was one of the first physicians to apply the concepts of physics and mechanics to the human and animal body, viewing the bones and joints as levers and the heart as a pump.

Related Content

Wonderful Works on Horses By Margaret Kaiser

Wonderful Works on Horses in Circulating Now

A drawing illustrating people in white coats collect blood from horses.

Living Factories in From DNA to Beer: Harnessing Nature in Medicine & Industry

The Horse: A Mirror of Man

The content of this website is drawn from a display held in the History of Medicine Division of the National Library of Medicine, December 5, 2005 to April 28, 2006.

The show was curated by Michael North who was then Head of Rare Books and Early Manuscripts at NLM.

You can view the original website created to accompany the display archived in the NLM Institutional Archives web collection.