Horse hair offers insights into health, genetics, stress, and even history

That sleek, shiny coat. That thick, flowing mane. The full, elegant tail.

We love horses’ hair—so much so that throughout the past 5,000 years we’ve bred horses based on their coat/hair color and quality. And long before that, humanity began portraying the beauty of equine hair in drawings, paintings, sculptures, animations, and other artwork.

Beyond that aesthetic appeal, horses’ hair contains abundant information about their health, welfare, breeding, drug intake, and even ancient history. 

In this article we’ll provide an overview of the latest knowledge about what horses’ hair can tell us.

What’s in a Strand of Hair?

Hair forms at the bulb, nestled in the follicle under the skin, and grows into a multilayered root that—unless it’s white—is colored by melanin. The shaft extends beyond the skin and progressively moves outward as the bulb produces new growth. There, polypeptide chains of amino acids such as glutamic acid, cysteine, and serine create strong keratin fibers that align to create a thick central cortex (sometimes surrounding a thin core called the medulla) and an outer cuticle level where fibers overlap like scales.¹

Hair consists mainly of keratin, water, melanin pigments, lipids—such as triglycerides, phospholipids, and cholesterol—and minerals, including iron, magnesium, zinc, and copper. Its chemical makeup is 45% carbon, 28% oxygen, 15% nitrogen, 7% hydrogen, and 5% sulfur.

Researchers have suggested equine coat hair usually matches human hair in thickness, while tail hair measures about 50% thicker and mane hair falls somewhere between. Horse hair offers strength, resilience, and natural water resistance.²

Appearance: A Simple Health Measure in Horses

A good look at a horse’s coat, mane, and tail can give basic insights into health status, says Carissa Wickens, PhD, associate professor and extension equine specialist at the University of Florida (UF), in Gainesville