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Why Your Horse’s Winter Coat Won’t Grow: Solving the Mystery

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There’s nothing more comforting than seeing your horse’s coat grow thick in preparation for the harsh winter months. But what do you do when that winter coat isn’t growing? It turns out there are a number of factors that can impact a horse’s ability to grow that all-important warm winter coat.

It can be concerning and frustrating if your horse is not growing a winter coat. There are several reasons why this might happen, including insufficient exposure to cold weather, health issues, grooming habits, and diet.

In this article, I share what I learned to help my horse grow the perfect winter coat, from the importance of exposure to cold weather to the role of health and management practices and even nutrition. If you’re wondering why your horse isn’t growing a winter coat, join me as I explore the surprising reasons and what you can do to help.

Picture of horses with healthy winter coats.
Horses with healthy winter coats

Common Reasons for Lack of Winter Coat Growth

As horse owners, we often anticipate the growth of a thick, warm winter coat to keep our equine friends comfortable during the colder months. However, sometimes our horses may not grow a winter coat as expected, leaving us puzzled and concerned.

Before we delve into the hidden culprit behind this issue, let’s first explore some of the common reasons that might be preventing your horse from growing a winter coat. These factors can range from dietary imbalances to health problems and environmental influences. By understanding these common reasons, we can better address the mystery at hand.

Insufficient Exposure to Cold Weather

One of the main triggers for the growth of winter coats in horses is exposure to cold weather. The decrease in daylight hours and drop in temperature signals to the horse’s body that winter is approaching.

This causes a release of hormones, including melatonin, which stimulate the growth of hair. The hair follicles on the horse’s skin respond to the hormonal signals by producing more hair, leading to the growth of a thicker and longer winter coat.

The length and thickness of the coat will vary depending on the breed, age, the overall health of the horse, and the amount of exposure to cold weather. However, if your horse is living primarily indoors and not getting enough time outside, it may not get the exposure they need to grow a healthy, thick coat.

To provide appropriate exposure to cold weather, consider turning your horse out for a few hours a day, especially during the colder months. If you don’t have a pasture or outdoor area for your horse, try taking them for walks or riding them in colder weather to help trigger hair growth.

Picture of a horse with a patchy winter coat.
Rain rot

Health Factors

Health conditions can greatly impact a horse’s ability to grow a winter coat. Here are some of the most common health problems that can interfere with hair growth:

  1. Anemia: Anemia, which is a lack of red blood cells, can prevent the horse’s body from receiving enough oxygen to produce a thick coat.
  2. Hormonal imbalances: Hormonal imbalances, such as those caused by Cushing’s disease or thyroid problems, can impact the horse’s ability to stimulate hair growth.
  3. Skin infections: Skin infections, such as ringworm or other fungal infections, can prevent the growth of a winter coat and cause hair loss.
  4. Allergies: Allergies can cause skin irritation and prevent the growth hair.
  5. Parasites: Internal parasites, such as worms, can weaken a horse’s immune system and prevent your horse from growing a thick coat.

It is important to address any health issues that your horse may be experiencing in order to promote the growth of a healthy winter coat. Your veterinarian can help diagnose any health problems and provide appropriate treatment. Regular check-ups and preventive care can also help keep your horse healthy and ensure they are able to grow a proper coat in the winter.

Management Practices

The way you manage your horse can also impact hair growth. For example, if you’re frequently grooming your horse, you may be removing the natural oils that help protect and insulate their skin and coat. Overgrooming can also damage the hair follicles, making it difficult for the horse to grow a good coat. If you need to groom your horse, use a gentle brush and avoid using products that strip their skin and coat of natural oils.

Another management practice that can impact winter coat growth is stabling horses too much. Allowing your horse to spend time outside and providing plenty of exercise can help promote winter coat growth. In addition, keeping a blanket on your horse can also hinder its ability to grow a winter coat. Horses naturally grow thicker winter coats in response to cold weather exposure.

When you constantly cover your horse with a horse blanket, you prevent them from getting the necessary exposure to the cold weather that triggers hair production. Using a blanket can also lead to overheating, which can cause sweating and skin irritation.

While it can be tempting to keep a blanket on your horse for added warmth, it is important to weigh the potential benefits against the risks. If you do choose to use a blanket, it is important to monitor your horse’s body temperature and to remove the blanket periodically to allow for proper ventilation and exposure to cold weather.

Additionally, if you’re clipping your horse’s coat too short, you may be hindering its ability to grow a thick coat. To promote winter coat growth, try to minimize grooming and avoid clipping your horse’s coat until the winter has passed.

Nutritional Factors

A diet lacking essential nutrients can prevent the horse’s body from producing a winter coat or can result in a thin, patchy coat that does not provide adequate protection from the cold. Additionally, horses that are underweight or have poor body conditions may not have the energy or resources necessary to grow a thick coat. To ensure your horse is getting the proper nutrition, feed them a balanced diet and consider adding supplements as needed.

Some key nutrients to focus on include:

  1. Protein: Horses need protein to grow and maintain their skin, hair, and other tissues. Good sources of protein include hay, pasture, and grain such as oats and corn.
  2. Biotin: This B-vitamin is essential for healthy skin and hair growth. Good sources of biotin include soybeans, yeast, and alfalfa.
  3. Zinc: This mineral is essential for skin health and can help support winter coat growth. Good sources of zinc include grain, soybeans, and alfalfa.
  4. Essential fatty acids: Omega-3 and Omega-6 fatty acids are important for skin and hair health. Good sources of these fatty acids include flaxseed, fish oil, and vegetable oil.

It is also essential to provide horses with adequate amounts of vitamins A and E, as these vitamins play a role in skin health and can support hair growth. Providing your horse with adequate access to fresh water is also crucial, as hydration is necessary for skin and hair health.

Picture of a person riding a horse in the snow.
Horse without much of a winter coat.

The Hidden Culprit: Artificial Lighting

As we search for the mystery behind our horse’s missing winter coat, we stumble upon a hidden culprit – artificial lighting. You might be surprised to learn that something as seemingly harmless as artificial light can have a significant impact on your horse’s health and well-being.

A. The effect of artificial lighting on horses

1. Disruption of melatonin production
Melatonin is a hormone that plays a crucial role in regulating sleep-wake cycles and seasonal changes in animals, including horses. When exposed to artificial light during nighttime hours, horses may experience a disruption in their melatonin production. This interference can result in physiological changes that affect the growth of their winter coats.

2. Disturbance of natural circadian rhythm
Horses, like humans, have a natural circadian rhythm that is influenced by light and darkness. Artificial lighting can disturb this rhythm, causing an imbalance in their biological clock. This disturbance not only affects their sleep patterns but also the natural progression of winter coat growth.

B. Sources of artificial lighting

1. Stable and barn lights
Many horse owners use lights in stables and barns to provide better visibility and safety during nighttime hours. However, these lights can contribute to the disruption of your horse’s melatonin production and circadian rhythm.

2. Outdoor security lights
Outdoor security lights are essential for the safety of your property, but they can also affect your horse’s natural light exposure. When these lights shine into your horse’s living area, they can interfere with their sleep and winter coat growth.

3. Indoor arena lights
Indoor arenas often require bright lighting to ensure safe and enjoyable riding experiences. However, if your horse spends a significant amount of time in an indoor arena with artificial lighting, it can disrupt their natural light exposure and negatively impact their winter coat growth.

C. Artificial lighting’s impact on winter coat growth

The disruption of melatonin production and the disturbance of your horse’s natural circadian rhythm caused by artificial lighting can have a noticeable effect on winter coat growth. The lack of a winter coat can leave your horse more susceptible to the cold and less prepared for the harsh winter months. Understanding the hidden impact of artificial lighting can help you take the necessary steps to ensure your horse’s well-being and promote the growth of a healthy winter coat.

Picture of our horse in a stall.
Horse kept in a stall

Detecting and Resolving the Issue

Now that we’ve identified artificial lighting as a potential cause for your horse’s lack of winter coat growth, it’s time to detect and resolve the issue. By addressing the problem, we can help our equine friends grow healthy winter coats and maintain their overall well-being.

The first step is to assess the amount of artificial light exposure your horse is experiencing. Observe your horse’s environment during the day and night to identify any sources of artificial lighting that could be affecting them. Take note of barn and stable lights, outdoor security lights, and indoor arena lights that may be disrupting your horse’s natural light exposure.

Next, you need to establish a natural light schedule. To help your horse develop a proper winter coat, it’s essential to establish a more natural light schedule. This can be done in the following ways:

1. Gradual adjustments to reduce stress
Sudden changes in lighting can be stressful for your horse, so it’s important to make gradual adjustments to their light exposure. Start by dimming the lights during nighttime hours or reducing the time the lights are on in the evening. Over time, continue adjusting the schedule until your horse is experiencing a more natural light and dark cycle.

2. Utilizing timers and sensors
Make use of timers and sensors to automate the lighting in your horse’s environment. Timers can help regulate the lights by turning them on and off at specific times, while sensors can detect natural light levels and adjust the artificial lighting accordingly. This will help ensure your horse has consistent exposure to natural light cycles and minimize disruptions to their circadian rhythm.

As you make changes to your horse’s light exposure, keep a close eye on their progress. Monitor their winter coat growth and overall health to ensure the adjustments are having a positive impact. If you don’t see improvements in your horse’s winter coat after implementing these changes, consult with a veterinarian to rule out any underlying health issues.

By staying attentive to your horse’s needs and making the necessary adjustments, you can help them grow a healthy winter coat and stay comfortable during the colder months.

Additional Strategies for Promoting Winter Coat Growth

While addressing artificial lighting is crucial, there are other steps you can take to further promote your horse’s winter coat growth. Implementing these additional strategies will not only contribute to a healthy winter coat but also support your horse’s overall well-being.

A. Ensuring a balanced diet

A balanced diet is essential for your horse’s overall health and winter coat growth. Make sure your horse is receiving the right nutrients, vitamins, and minerals by providing high-quality hay, grains, and supplements as needed. Consult with a veterinarian or equine nutritionist to develop a suitable feeding plan for your horse’s specific needs.

B. Regular grooming and care

Grooming your horse regularly can help stimulate their skin and hair follicles, promoting winter coat growth. Brushing also helps remove dirt, debris, and dead hair, allowing new hair growth to come through. Additionally, regular grooming allows you to closely monitor your horse’s skin and coat condition, making it easier to spot any issues early on.

C. Addressing potential health concerns

If your horse is still struggling with winter coat growth despite addressing artificial lighting and implementing the strategies mentioned above, it’s important to consider potential underlying health issues. Parasites, hormonal imbalances, and other medical conditions can all affect your horse’s ability to grow a winter coat. Consult with your veterinarian to rule out any health concerns and develop an appropriate treatment plan if necessary.

By combining these additional strategies with adjustments to your horse’s light exposure, you can help ensure they grow a healthy, protective winter coat and remain comfortable during the colder months.

Importance of a Winter Coat

A winter coat is important for horses as it provides insulation and protection from cold and wet weather during winter months. It helps to regulate body temperature, prevent heat loss, and protect the skin from damage due to harsh weather conditions.

Additionally, a winter coat provides protection from the sun and wind and can help reduce the risk of certain skin conditions. Maintaining a healthy winter coat is important for the overall health and comfort of a horse during the winter season.


If your horse isn’t growing a winter coat, there could be a number of factors at play. From lack of exposure to cold weather to health conditions, grooming practices, and nutrition, it’s important to consider all of the factors that could be impacting your horse’s coat growth.

Understanding the mystery behind your horse’s lack of winter coat growth is essential for their health and comfort during the colder months. By identifying the hidden culprit of lack of hair growth, artificial lighting and addressing this issue, you can help your horse adapt to a more natural light schedule.

In addition, implementing additional strategies such as ensuring a balanced diet, regular grooming, and addressing potential health concerns will further support your horse’s winter coat growth. By taking these steps, you can provide your equine companion with the care they need to thrive in any season, fostering a healthy, comfortable, and well-prepared horse.


How long does it take for a horse to shed its winter coat?

It typically takes four to six weeks for a horse to shed its winter coat. However, factors such as exposure to sunlight and warmer temperatures can impact the speed of shedding.

Do all horses grow a winter coat?

Most horses grow a winter coat in the winter. However, in warm climates, they may not need to, and some may have trouble growing one because of health conditions or management practices.

What temperature does a horse need a winter blanket?

A horse may need a winter blanket when the temperature drops below 40°F, depending on factors such as the horse’s age, health, and coat thickness. However, it’s important to monitor the horse’s body condition and adjust blanket use accordingly to prevent overheating or chilling.