7 Reasons Why Is Your Horse Losing Hair (Diagnosis & Prevention)

Have you noticed bald spots on your horse’s skin?

Seeing your adorable equine lose its soft, shiny hair can be alarming.

Horses lose hair because of heat, parasites, bacteria, insects, and even serious diseases such as cancer.

These factors may affect the hair follicle causing hair to fall off, slow down hair growth, or cause the horse to scratch so much, leading to bald patches that can worsen over time.

If you are wondering, ‘why is my horse losing hair?’ you have come to the right place.

In this article, I will explain the most common causes of hair loss in horses.

You will also find some typical treatments veterinarians use to manage horse hair loss problems.

So, let’s divine in!

Common Reasons for Hair Loss in Horses

There are many reasons why your horse might develop bald spots.

One thing is for sure, the cause is usually external or an internal medical condition.

Here are some of the common causes of horse hair loss issues:

1. Insects


Tiny as they are, insects can cause massive havoc on your horse’s wellbeing.

Not only is their bite painful and itchy, but these critters can also carry dangerous disease and transmit it to your equine pet.

  • Biting gnats

Biting gnats are the insects most commonly associated with hair loss in horses.

These tiny bugs like to gather around the horse’s belly, mane, and tail.

They inflict painful bites and create open wounds on the horse’s skin. The horse reacts by vigorously scratching itself against items such as walls, poles, and trees.

The excessive scratching caused by bites from the gnats causes the horse to quickly lose several hair strands.

If the gnats are not eliminated, they will continue to bite the horse, causing more scratching and more hair loss.

Biting gnats are also transmitters of Onchocerca cervicalis, a parasitic worm causing itching and small but painful cuts on the horse’s skin.

  • Horse Flies

Another insect that is likely to cause your horse to lose hair is the female horse fly.

These insects cut into the skin, causing bleeding spots.

The blood attracts other insects, causing the horse to itch further. Excessive itching can cause hair loss.

  • Stable Flies

Stable flies are prevalent in the spring. While other insects bite, these boreholes on the horse’s skin and suck blood.

The wounds these flies create can cause intense itching, resulting in random bald patches that can worsen in days.

Stable flies, which resemble house flies, also transmit disease and infect the wounds, leading to skin infections.

  • Ticks

Ticks live in grass and climb up the horse’s leg, and easily spread to the rest of the body.

The upside is you can spot and remove ticks on the horse’s skin during your regular grooming sessions.

A tick infestation will cause your horse to itch, rigorously twitch its tail, and scratch itself against poles, trees, and walls to ease the itch.

2. Fungal Infections

Fungal Infections

Fungus can cause a skin infection known as Dermatophytosis. This infection resembles what we commonly know as ringworms, round, bald, sore patches on the skin.

Generally, horses are more prone to fungal infections in the cooler months. Dark and damp barns can also be breeding grounds for fungi.

That said, it is also common for fungal infections to attack your horse even when the climate is warm and humid.

Fungal diseases spread quickly among horses, with the infection becoming fully blown one to six weeks after the fungus infects the horse.

Dermatophytosis wounds are oval in shape and crusty and typically found around the chest, neck, face, hindquarters, and saddles.

The wounds can sometimes be itchy and painful. The resulting inflammation can cause hair loss, with strands of hair loss breaking around the edges of the wound.

3. Bacterial Infection

Bacterial Infection

The Dermatophilus congolensis bacteria cause a condition commonly known as dew poisoning, rain scald, or rain rot.

The bacterium thrives in places with high moisture levels and takes advantage of broken skin.

Leaving your horse out in the rain can also soften its skin, making it more prone to cuts and abrasions.

The lower limbs, saddle, muzzle, face, and rump as the most prone to skin infections caused by the bacteria.

Rain rot lesions are scaly and their pinch on the horse’s hair, leaving behind bald spots. Younger horses with a weaker immune system are more susceptible to this condition.

These painful wounds can also cause your horse to itch incessantly, resulting in further hair loss.

Dermatophilus can be difficult to diagnose. Some horses affected by this organism may not show physical signs and symptoms. But, they can still spread the bacteria to others in the stable.

4. Seasonal Hair Loss

Seasonal Hair Loss

Sometimes, your horse might lose hair for a less serious reason. Horses undergo seasonal hair loss and growth.

There is a period when the horse enjoys quick spurts of hair growth. This period is known as anagen. The horse then goes through telogen, the resting period before it loses old hair to make way for new hair.

It takes about six weeks for a horse to grow new hair. During this period, you might notice a few bald spots on your horse.

But, unless you are worried about an underlying medical condition or an infection, seasonal hair loss should not worry you too much.

5. Sweat and Heat

Sweat and Heat

Another benign reason for hair loss in horses is sweat and heat.

When sweat is trapped under the mane, it is absorbed into the skin and hair follicles.

The excessive sweat softens the follicle, causing the hair to fall off easily.

When sweat dries on the horse’s skin, it can irritate, leading to hair loss.

The dried sweat can cause itchiness, and when your horse rubs itself, 6the result can be random baldness on areas of the skin.

The face, eyes, and ears are usually the most affected by sweat and heat during the warm months.

When your horse experiences an intense itch and hair loss, it might avoid having its faced touch due to the discomfort.

6. Skin Cancer

Skin Cancer

Horses can suffer from a benign skin cancer known as sarcoid, which can cause hair loss.

Sarcoids look like flat, rippled, hairless patches on the horse’s skin. The wounds are neither painful nor are they itchy.

These lesions are contagious and can be spread from one horse to another through contaminated equipment.

Viruses can also transfer the cancerous infection from one horse to another.

Basic hygiene can help prevent the spread of skin cancer from one infected horse to other healthy horses.

Like other common causes of hair loss in horses, sarcoids can only be diagnosed by a veterinarian. A biopsy of the lesion is usually needed for diagnosis and to find a suitable treatment for the cancerous cells.

7. Selenium Allergy

Selenium Allergy

Selenium is a mineral found in soil.

Excessive amounts of the mineral can result in toxicity when horses ingest plantation that has absorbed selenium.

Feeding horses with selenium-rich hay can also cause an allergic reaction, resulting in hair loss.

Selenium allergy or intolerance causes the tail hairs and mane to thin and fall. Eventually, the horse develops large bald patches on the skin.

Several selenium allergies can also cause the hooves to crack and will further affect the hoof capsule.

Removing affected horses from pastures with high selenium content or providing hay with a lower selenium content can help mitigate and reverse the effects of selenium toxicity.

Diagnosis And Prevention Of Hair Loss In Horses

Diagnosis And Prevention Of Hair Loss In Horses

The appropriate treatment for horse hair loss problems will depend on the diagnosis.

Your veterinarian will perform any number of tests depending on the observed physical symptoms.

Common tests include a skin exam, rectal exam, dental check, hood tests, urinalysis, serum allergy tests, blood count tests, and skin scrape.

It is important to inform your veterinarian about recent gnat, horsefly, or tick infestations in your area. This will allow them to rule out any insect-caused hair loss.

Your vet might recommend bathing your equine with antimicrobial shampoo to relieve the itchiness. Antibiotics or antihistamines can be prescribed in case of a bacterial infection or allergic reaction respectively.

Tropical miconazole creams can relieve fungal infections that cause hair loss in horses. These creams also help to alleviate itching and can promote hair growth.

Lastly, observe high standards of hygiene in the stalls and with your horses. Parasites, bacteria, and fungi thrive in damp, dark, and dirty environments.

Keep your stalls clean and shampoo your horses regularly to avoid the transfer of otherwise deadly diseases.

Summary: Why Is My Horse Losing Hair?

There are many reasons why your horse might be losing hair. Some reasons are benign, like sweat and heat that can cause the hair follicles to fall off.

Insect bites are the most common cause of hair loss in horses. Bacterial, parasitic, and fungal infections can also cause intense itching, and inflammation resulting in significant hair loss.

Aside from seasonal hair loss, you should consult with a veterinarian to find out the exact reason why your equine is losing hair.

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