The Long & Short of Equine Coats

Last Updated on February 23, 2022 by Allison Price

Understanding how your horse’s hair grows is key to bringing out his natural shine.Your horse’s color is so important to his identity, that you often mention it first when talking about him. A palomino Quarter Horse. A leopard Appy.Brushes with finer bristles do a better job dispersing coat oils than those with thicker bristles.

There’s more to the horse’s coat than just color. The hair of a horse is an important part of his largest organ, the skin. The coat acts as a barrier against insects and the elements throughout the year. It thins in hot weather and then grows long enough to provide insulation during winter. Amazing adaptation is the hallmark of the equine coat.

Horse owners should be aware that a horse’s coat is an indicator of his overall health. Enjoying a horse’s rich, shiny coat is one of the many benefits of caring for him. A dull, rough, or sparsely trimmed coat could be a sign of illness, nutritional deficiencies, or hormonal imbalances.

You want your horse to look great. It is important to consider the structure and function and the biology behind the horse’s coat. Let’s take a closer look at how the science works to achieve shine.


The horse’s hair is composed of millions of hairs. Each layer has its own distinct layers. A microscope can show you a small core of a horse’s hair shaft. The medulla is a collection of loosely packed cells, which shrink when dehydrated, leaving open spaces. The medulla’s diameter determines the hair’s diameter. Thicker hairs and tail hairs have bigger medullas, while those with thinner bodies tend to have smaller medullas. The medulla is prominent in gray hairs and white hairs. However, it is absent entirely in fine hair.

The cortex is the next layer, and it provides the bulk of your shaft. This layer contains 85 percent of keratin. Keratin is a fibrous protein which also forms hoof walls and your fingernails. These protein fibers are parallel and cross-linked to increase their strength. The cortex is made up of keratin and fats. It also contains melanin, which is a black or brown pigment that gives color to the skin, as well as water and minerals.

The cuticle is the outermost layer of hair shaft. It is composed of many overlapping cells, giving it a rough and almost scaly appearance. The cuticle is what anchors the hair shaft into the follicle. It also plays an important role when we see the shine in a horse’s coat.

A follicle is an organ that contains muscles, glands, and blood vessels. Each hair grows from it. Different follicles can produce different hair cells. For example, the ones at the crest are better equipped to produce thicker hair and a different color than those at the flanks.

The arrector pili muscle is attached to the horse’s hair follicles. The arrector pili muscle contracts to lift hairs from the skin’s surface. This helps trap air between the hairs and provides insulation. On a cold winter day, you will notice a fuzzy feeling in the coat of a fluffy pony. This is his arrector pili muscles.

A sebaceous gland is located next to each hair follicle. This gland produces sebum, which coats each strand. Sebum acts as a barrier between the skin and hair. It repels water and prevents the growth of micro-organisms. Additionally, it slicks the cuticles, which reflect light uniformly in a way our brains and eyes interpret as shine. A hair without enough oil will have a rough outer layer that reflects light randomly and gives it a dull appearance.

The hair root, matrix, and papilla are located at the base of the follicle. These cells, which include a collection of cells known as the “bulb”, regulate each shaft’s growth and eventual shedding. These cells are responsible for determining when horsehair will cover your truck seats each spring.

The Long & Short of Equine Coats


Hair, including yours and that of your horse, develops in three phases.

* During the anagen phase, the bulbs’ cells are actively producing the hair shaft. This phase is when the hair grows longer from the follicle. The speed at which this happens and the length of the strand’s growth depends on many factors, including genetics.

* The catagen phase, which is relatively short, is a transitional period during which growth stops and the follicle starts to shrink.

* The final telogen stage is when hair stops growing and it is not connected to a blood supply. Until the anagen phase, the hair is literally pulled out by a new hair.

These three phases are common among hairs. While you will lose approximately 100 hairs every day from your head, many others are growing simultaneously. There are small changes in hair growth rates that vary with seasons, peaking in the late summer or early autumn, and hormonal fluctuations. However, as a rule, human hair follicles do not work in sync. This is why there is no “shedding season” for you. Your horse does.

Photoperiods control horse shedding. Photoperiods are controlled by light receptors in horses’ eyes. They relay changes in daylight duration to the pineal gland of his brain, which makes melatonin. The late autumn brings a decrease in daylight hours, which causes coat growth.

These changes can take some time. Studies show that coat changes take place between five and eight weeks after day-length transitions. Your horse’s winter coat will be growing in by August, when the days are shorter. It may also be comforting to recall that even though it is freezing cold outside, your horse’s sleek summer coat is already growing in his hair follicles.

Sometimes, artificial photoperiods can be used to control the growth of coats in show horses. For example, horses may be kept in barns that remain lit after sunset to simulate a longer photoperiod. This will delay their winter coat growth. A horse can also be stimulated to shed its winter coat sooner by artificially increasing the time he perceives. You can’t manipulate photoperiods so there are some grooming methods you can use to help the shedding process. (See “Speeding Up Shedding,” pages 50 and 51). It will typically take four weeks, or longer.


It’s easy for people to forget that the appearance of your horse’s hair is affected by more than just what they can do. Hair follicles, which are complex and metabolically active tissues, can be affected by the same negative and positive influences as the rest of the horse’s organs.

A horse with a poor diet can have dull or brittle hair. However, malnutrition is often visible in other areas. It is important to check your horse’s diet for signs of malnutrition.

Selenium toxicosis is the opposite. This happens when there is too much trace mineral selenium. This is a condition that occurs when horses graze on pastures with high levels of selenium. It can cause brittle manes and tail hairs. It is believed that excess selenium replaces sulfur in the hair’s amino acid chains, which reduces its strength. Selenium toxicosis can often be diagnosed by a lackluster mane, tails, and hooves.

Before diligent deworming was a common practice, horses with heavy parasite burdens could have dull coats as their nutritional resources were depleted by the worms they carried. Although it is unlikely that a dull, well-treated horse has parasite issues, it is worth checking to see if there are any eggs.

Sometimes, an illness can cause more than dull and brittle hair. Some diseases can cause hair loss. Anagen defluxion is a condition where a physiologic stressor, such as high fever or an infectious disease, interferes with the anagen stage of hair growth. The result is that hair falls out in days and growth ceases immediately. Telogen defluxion is a similar condition. However, hair loss doesn’t usually occur for up to three months after the stressor. Although the resulting baldness may be widespread, it is more common to see small areas. Most cases of defluxion result in normal hair growth once the underlying cause is addressed.

Defluxion differs from “patchy” shed, in which the winter coat is shed in distinct patterns each spring. Horses tend to shed their head, shoulders, and rump first, while the rest of the body takes longer. Although it’s not clear why this happens, it’s not something to be concerned about. However, the horse’s coat might not look its best until the process has been completed.


This doesn’t mean your grooming habits won’t affect the appearance of your horse’s hair. Actually, the reverse is true. A good coat foundation is good health. However, a great grooming routine is necessary to achieve the stunning “bloom” that makes a coat truly stand out.

Consider how the tools and products you choose will impact your horse’s overall health and long-term health.

Currycombs are able to loosen dirt and other hard-to-reach areas, making it easier for you to clean. Use a comb that has long, flexible fingers and keep it in your hand. The more you can curry your horse, the better. Consider using a “cactuscloth” if your horse is sensitive or tickly. This is a towel made with agave fibers and it offers many of the same benefits.

* Finer bristles do a better job of dispersing coat oils than those with thicker bristles. Even if you have a thick winter coat, don’t forget to finish the job.

To minimize hair loss, use the widest tooth comb you can find for your horse’s tail and mane. The growth of mane and tail hairs is slow but steady. It takes many years to replace a lost tail hair. Begin at the base and work your way up. If necessary, divide the hair into sections and remove tangles manually (a quick spray of detangling spray may help). Do not try to comb hair straight from the crest or dock. This will only lead to frustration, and may result in broken hairs.

Shampooing your horse’s hair is a matter of reducing the amount of shampoo you use. Shampoos “grab” dirt particles and allow them to be easily rinsed off. Shampoos can also grab oil particles. These oils protect the skin of your horse and give it a shiny coat. A lustrous coat can be caused by too much shampooing. You can rinse your horse with water if he is not very dirty but is still sweaty. You can save the sudsing for special occasions. Natural oils take a while to recover so it is best to shampoo your horse before the event.

Use a shampoo that is formulated for horses and not dish detergent. This can cause skin irritations in horses. Follow the instructions on the label when using shampoos. Many shampoos will require that you add the shampoo to a bucket of warm water. Then, you should spongy the soap onto the horse. The suds will then rinse easily. The soap residue can cause a dull and irritated coat.

* Equine hair conditioners can restore oil from the skin and hair that has been washed out by shampooing. They can help to detangle hair and prevent “frizzies”, on a molecular basis. A conditioner is a great idea if you shampoo your horse often. Follow the instructions on the label. For maximum results, some conditioners should be left on for at least a few minutes before you rinse.

Shine sprays are made up of silicone, keratin, or panthenol. They bond to the hair shafts and smoothen the cuticle which increases light reflection. While these products can be used to add an “finishing touch” to a well-groomed horse’s appearance, they cannot replace regular grooming. They can cause a slick coat, which can affect saddle stability. You can avoid accidental application by spraying the towel on the horse and wiping it clean.

Take a moment to notice your horse’s beautiful spring coat as you look back at him.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!