Scratches and Hair Loss in Horses: Causes, Treatment and Prevention

By Dr Duncan Houston

Hair loss, scabs, crusting, swelling, and soreness around a horse’s lower legs are often grouped under one familiar name: scratches.

Scratches is also called equine pastern dermatitis, mud fever, greasy heel, mud rash, cracked heels, or dew poisoning. The names vary, but the pattern is usually similar. The skin around the pastern, heel, fetlock, or lower cannon becomes inflamed, damaged, infected, or irritated.

The important point is that scratches is not one single disease. It is a reaction pattern. Moisture, mud, bacteria, fungi, mites, allergies, insect bites, contact irritation, sunlight sensitivity, heavy feathering, and chronic lower-leg disease can all contribute. That is why the same cream may help one horse and fail completely in another. UC Davis describes pastern dermatitis as a disease complex triggered by different causes, not a single diagnosis. (Center for Equine Health)

Quick Answer

Scratches in horses is inflammation of the skin around the pastern and lower leg, often causing hair loss, scabs, crusts, redness, swelling, oozing, itching, pain, or lameness. Mild cases may improve with dry management, gentle cleaning, careful clipping, and vet-directed topical treatment. Swollen, painful, wet, oozing, recurrent, lame, or heavily feathered cases need veterinary assessment because bacteria, fungi, mites, allergy, photosensitivity, or deeper infection may be involved.

What Are Scratches in Horses?

Scratches is the common name for equine pastern dermatitis.

It most often affects the back of the pastern, but it can also involve the heel bulbs, fetlock, and sometimes extend up the lower limb. UC Davis notes that pastern dermatitis is commonly characterized by inflammation on the back of the pasterns and can occur in any breed, although draft breeds and horses with heavy lower-leg feathering are more commonly affected. (Center for Equine Health)

Typical signs include:

• Hair loss around the pastern or lower leg

• Dry scabs or thick crusts

• Red or inflamed skin

• Flaky or scaling skin

• Oozing or discharge beneath crusts

• Swelling around the pastern or lower limb

• Pain when the area is touched

• Itching, rubbing, stamping, or chewing

• Lameness in more severe cases

In practice, the scabs are only the visible part of the problem. The real question is what damaged the skin barrier in the first place.

Why Does Scratches Cause Hair Loss?

Hair loss usually happens because the skin and hair follicles are inflamed.

The horse may lose hair because:

• Scabs lift hair away from the skin

• Infection affects the hair follicles

• The horse rubs or chews the area

• Moisture softens and weakens the skin

• Mites or insects trigger self-trauma

• Chronic inflammation thickens and damages the skin

• Topical products or harsh cleaning irritate the area further

MSD Veterinary Manual explains that dermatitis can cause itching, scaling, redness, thickening, hair loss, crusting, discharge, pain, and secondary bacterial or yeast infection. (MSD Veterinary Manual)

Hair loss by itself is not the most worrying sign. Hair loss with heat, swelling, pain, discharge, spreading lesions, or lameness is much more concerning.

What Causes Scratches?

Scratches usually develops when the skin barrier is damaged, then infection or inflammation takes over.

Common triggers include:

Wetness and humidity are major perpetuating factors. Purdue recommends keeping affected horses off wet pasture, using clean dry bedding, drying legs before stabling, and avoiding boots or wraps that trap moisture. (Purdue Vet School)

Why Feathered Horses Are Higher Risk

Heavy feathering is beautiful, but it makes skin disease harder to spot and harder to treat.

Long lower-leg hair can trap:

• Mud

• Moisture

• Sweat

• Skin flakes

• Scabs

• Bacteria

• Fungi

• Mites

• Topical products that never reach the skin

University of Melbourne equine guidelines note that severe pastern dermatitis is most commonly seen in cob and draft-type horses, and that feathered limbs are a risk factor. In feathered horses, clipping can be critical for proper examination because the skin lesions may be hidden underneath the hair. (Faculty of Science)

This does not mean every feathered horse needs permanent clipping. It means that when the horse is sore, scabby, swollen, or repeatedly affected, you need to see the skin properly.

Severity Guide: How Worried Should You Be?

The most important decision point is simple: dry scabs are one thing; a hot, swollen, painful, lame lower leg is another.

What Else Can Look Like Scratches?

Not every scabby lower leg is simple mud fever.

Important rule-outs include:

Bacterial pastern dermatitis
This is common when the skin is wet, cracked, oozing, swollen, painful, or producing yellow or white discharge.

Fungal infection or ringworm
Fungal disease can cause hair loss, scaling, crusting, and spread through shared brushes, rugs, tack, or direct contact.

Chorioptic mange
Chorioptes mites are an important cause in draft, cob, pony, and feathered horses. Signs may include stamping, chewing, rubbing, scabs, thickened skin, and recurring lower-leg irritation. The University of Melbourne guidelines describe Chorioptes bovis as the most frequently cited parasitic cause in draft and cob or pony breeds. (Faculty of Science)

Photosensitivity
White or unpigmented skin may become inflamed after sunlight exposure. This may be linked to plant exposure, liver disease, or immune-mediated skin disease.

Contact dermatitis
Boots, wraps, bedding, detergents, sprays, shampoos, weeds, mud, or topical products can irritate the skin.

Pastern leukocytoclastic vasculitis
This immune-mediated condition can affect the lower limbs and may be aggravated by sunlight. It can look like recurring pastern dermatitis but needs a different plan.

Chronic progressive lymphedema
This is especially important in some heavy breeds. It can cause chronic swelling, thickened skin, folds, nodules, and recurrent infection.

Wounds or punctures
A hidden cut, wire injury, heel bulb wound, or pastern laceration can be mistaken for dermatitis once crusting forms.

This is why recurring scratches should not be treated as “just dirty legs.” If the trigger is wrong, the treatment will be wrong.

When Is This an Emergency?

Scratches is not always an emergency, but some cases need urgent veterinary care.

Call your vet promptly if your horse has:

• Lameness

• Marked swelling

• Heat in the lower limb

• Severe pain when the area is touched

• Rapidly spreading lesions

• Deep cracks or ulceration

• Bleeding skin

• White, yellow, or foul-smelling discharge

• Fever

• Depression or reduced appetite

• Severe itching, stamping, or self-trauma

• A suspected wound or puncture near the pastern

• No improvement despite several days of sensible care

• Repeated recurrence despite treatment

Purdue specifically advises veterinary attention when scratches is not responding to treatment, or when there is severe lameness, deep wounds, swelling, excessive heat, or white or yellow discharge. (Purdue Vet School)

If the leg is hot, swollen, painful, and the horse is lame, stop treating it like a cosmetic skin problem. That horse needs proper assessment.

How Vets Diagnose Scratches

Diagnosis starts with the pattern.

Your vet may ask:

• Which legs are affected?

• Is it one leg, both hind legs, or all four?

• Is the horse itchy, painful, or lame?

• Is the skin dry, wet, crusted, swollen, or oozing?

• Does the horse have heavy feathers?

• Are the legs white or unpigmented?

• Is this seasonal?

• Is the horse standing in mud, wet grass, or wet bedding?

• Are flies, mosquitoes, midges, or mites a concern?

• What products have already been used?

• Are other horses affected?

• Has this happened before?

Depending on severity, testing may include:

• Skin scrapings for mites

• Tape tests

• Hair plucks

• Cytology to look for bacteria or yeast

• Bacterial culture

• Fungal culture

• Biopsy in chronic, severe, or unusual cases

• Radiographs if lameness or deeper disease is suspected

UC Davis notes that diagnosis may involve biopsy, bacterial and fungal cultures, skin scrapings for ectoparasites such as Chorioptes mites, and radiographs when other causes of lameness need to be ruled out. (Center for Equine Health)

For recurrent or ongoing cases, the University of Melbourne guidelines also recommend collecting samples for bacterial and fungal culture and cytology because many causes are possible and can look clinically similar. (Faculty of Science)

What Should You Do Right Now?

1. Inspect the skin properly

Part the hair and look at the skin, not just the coat surface.

Check for:

• Hair loss

• Redness

• Scabs

• Thick crusts

• Moisture

• Oozing

• Swelling

• Heat

• Pain

• Cracks

• Discharge

• Lameness

Take photos every few days. This helps you and your vet judge whether the condition is improving, spreading, or simply changing appearance.

2. Move the horse to a dry environment

Dry management is one of the most important parts of treatment.

Practical steps include:

• Avoid deep mud

• Use clean, dry bedding

• Fill muddy gateways and areas around water troughs

• Dry legs before stabling

• Avoid repeated wetting and drying

• Keep the pastern area as dry as practical

If the skin is treated perfectly but the horse keeps standing in wet mud, recovery is much harder.

3. Clip long hair if needed

Clipping helps you see the true extent of the lesions and allows treatment to reach the skin.

This is especially useful if the horse has:

• Heavy feathers

• Matted hair

• Moist scabs hidden under hair

• Recurrent scratches

• Suspected mites

• Oozing or infection

Clipping should be done carefully. Do not scrape or cut the skin. Painful horses may need sedation for safe clipping and cleaning.

4. Clean gently

Gentle cleaning can help, but aggressive scrubbing can make the skin worse.

Your vet may recommend an antibacterial or antifungal shampoo depending on the suspected cause. Chlorhexidine is commonly used in many equine skin protocols, and the University of Melbourne guidelines note that crusts may need to be gently soaked and removed while bathing with a mild antibacterial shampoo, with drying afterward being important. (Faculty of Science)

The aim is to soften debris and reduce contamination, not scrub the leg raw.

5. Do not rip off dry scabs

Scabs may be painful and may cover raw tissue underneath.

If scabs need to be removed, they should be softened first and removed gently. If the horse is too painful to handle safely, stop and call your vet.

6. Dry thoroughly

Drying is not optional.

After washing, pat the area dry with a clean towel. Do not leave wet hair, wet feathers, or damp scabs against the skin.

Over-washing without drying is one of the classic reasons scratches drags on.

7. Apply medication only as directed

The right medication depends on the cause.

Your vet may recommend:

• Antibacterial ointment

• Antifungal treatment

• Anti-inflammatory topical medication

• Steroid-containing medication in selected cases

• Mite treatment

• Barrier cream on dry areas

• Oral antibiotics if infection is deeper or more severe

Do not layer multiple creams, sprays, oils, powders, and home remedies together. That usually makes the leg wetter, more irritated, and harder to diagnose.

Should You Wrap Scratches?

Sometimes, but not automatically.

A wrap may help in selected cases by protecting the skin or keeping treatment in place. But wraps and boots can also trap moisture, heat, and debris, which can make pastern dermatitis worse.

UC Davis recommends avoiding long-term use of boots and wraps that trap moisture, and Purdue gives similar advice for infected areas. (Center for Equine Health)

Do not wrap wet, oozing, swollen, infected, or painful skin unless your vet has advised it.

Common Mistakes Owners Make

Treating every case as mud fever

Mud is common, but it is not the only cause. Mites, fungi, bacteria, allergies, sunlight sensitivity, contact irritation, and chronic lower-leg disease can all look similar.

Pulling scabs off dry

This causes pain, bleeding, and more inflammation. Scabs should be softened first and removed only when appropriate.

Over-washing

Washing can help, but constant washing keeps the skin wet. Drying matters just as much as cleaning.

Using harsh products

Strong disinfectants, caustic scab removers, essential oils, bleach-like mixtures, and random stable-yard recipes can damage inflamed skin.

Wrapping damp legs

A wrap over damp skin can trap moisture and worsen the problem.

Ignoring mites in feathered horses

A cob, draft, pony, or heavily feathered horse that stamps, chews, rubs, and relapses should be checked for mites.

Stopping as soon as it looks better

The skin may look improved before the underlying trigger is controlled. Follow your vet’s treatment and recheck plan.

How To Prevent Scratches and Hair Loss

Prevention is about protecting the skin barrier.

Helpful steps include:

• Check pasterns regularly during grooming

• Keep legs as dry as practical

• Avoid prolonged turnout in deep mud

• Fill muddy areas around gates and water troughs

• Use clean, dry bedding

• Dry legs before stabling

• Avoid repeated wetting and drying

• Clip heavy feathers in recurrent cases if advised

• Do not leave boots or wraps on damp legs

• Do not share boots, towels, or grooming tools between affected horses

• Use fly control if insects trigger irritation

• Use sun protection strategies for white legs when needed

• Investigate recurring cases rather than repeating the same failed treatment

UC Davis prevention guidance focuses on avoiding recurrent moisture exposure, drying pasterns after bathing, keeping lower-leg hair clipped when needed, avoiding moisture-trapping boots and wraps, and maintaining clean, dry bedding. (Center for Equine Health)

The boring management details are what save you from the exciting vet bills. Dry legs, clean bedding, early checks, and sensible treatment are the foundation.

Will My Horse Recover?

Many horses recover well when the cause is identified early and treatment is consistent.

The prognosis is best when:

• The problem is caught early

• The skin is kept dry

• Scabs are handled gently

• Infection is treated appropriately

• Mites and fungal disease are not missed

• Harsh products are avoided

• The environment is improved

• Recurring cases are investigated properly

UC Davis notes that early, accurate diagnosis and appropriate treatment give the most successful outcomes and help prevent severe chronic changes. Secondary bacterial infections are common and can complicate diagnosis, treatment, and recovery. (Center for Equine Health)

Chronic cases can take longer, especially in heavily feathered horses or horses with chronic lower-leg swelling. In those horses, the goal may be long-term control rather than a once-and-done cure.

FAQs

Can scratches in horses go away on its own?

Very mild cases may improve if the trigger is removed and the area is kept dry. If there is swelling, pain, oozing, itching, discharge, recurrence, or lameness, it should not be left to resolve on its own.

Why is my horse losing hair around the pastern?

Hair loss around the pastern is usually caused by inflammation, scabbing, infection, rubbing, moisture damage, mites, or irritation. The pattern and severity determine whether this is mild dermatitis or something that needs a vet check.

Should I remove the scabs from scratches?

Do not pull off dry scabs. They should be softened first and removed gently only if appropriate. If your horse is painful, call your vet rather than forcing the scabs off.

What is the best treatment for scratches?

There is no single best treatment for every horse. The right treatment depends on whether the cause is moisture, bacteria, fungus, mites, allergy, sunlight sensitivity, contact irritation, or chronic lower-leg disease.

When should I call a vet?

Call a vet if the leg is swollen, hot, painful, oozing, lame, bleeding, spreading, not improving, or if the problem keeps coming back. Also call if the horse has heavy feathering and is stamping, chewing, or rubbing the lower legs.

Final Thoughts

Scratches is common, but it should not be treated casually.

The scabs and hair loss are only the visible signs. Underneath, there may be moisture damage, bacterial infection, fungal disease, mites, insect irritation, sunlight sensitivity, contact dermatitis, or chronic lower-leg disease.

The best approach is not to attack the scabs. It is to identify the cause, keep the skin dry, clean gently, treat infection or mites when present, avoid harsh products, and change the environment that allowed the problem to develop.

A few dry scabs may be manageable. A hot, swollen, painful, lame lower leg is not. Knowing that difference protects your horse’s comfort, skin health, and soundness.

If you are unsure whether your horse’s scratches are mild, infected, mite-related, fungal, allergy-driven, or urgent, ASK A VET™ can help you work through the signs and decide what to do next.