Scratches in Horses: How To Treat Equine Pastern Dermatitis

By Dr Duncan Houston

Scratches can look like a few harmless scabs at first, but it can become one of the most stubborn lower-leg skin problems in horses.

Also called equine pastern dermatitis, mud fever, greasy heel, cracked heels, mud rash, or dew poisoning, scratches usually affects the back of the pastern and heel region. In mild cases, you may see dry scabs and mild redness. In more serious cases, the skin can become swollen, painful, oozing, infected, itchy, thickened, and even lame.

The most important thing to understand is that scratches is not one single disease. It is a skin reaction pattern. Moisture, mud, bacteria, fungi, mites, allergies, insect irritation, photosensitivity, contact irritation, and chronic lower-leg disease can all play a role. UC Davis describes pastern dermatitis as a disease complex that can be triggered by different causes, which is why the same treatment does not work for every horse. (Centre for Equine Health)

Quick Answer

Scratches in horses is inflammation of the skin around the pastern, usually causing scabs, crusting, redness, swelling, oozing, pain, itching, or lameness. Mild cases may improve with dry management, gentle cleaning, clipping, and vet-directed topical treatment, but swollen, painful, oozing, lame, recurring, or heavily feathered cases need veterinary assessment. The best treatment depends on the underlying cause, not just removing the scabs. (Centre for Equine Health)

What Are Scratches?

Scratches is a common name for equine pastern dermatitis. It usually affects the skin on the back of the pastern, but it may involve the heel bulbs, fetlock, and sometimes extend up the lower limb in more severe or chronic cases. UC Davis notes that pastern dermatitis is commonly characterized by inflammation of the skin on the back of the pasterns and may also be called greasy heel, mud fever, mud rash, cracked heels, or dew poisoning. (Centre for Equine Health)

Typical signs include:

• Dry scabs around the pastern

• Thick crusts stuck to the skin

• Redness under the hair

• Oozing or moist areas

• Hair loss

• Scaling

• Swelling

• Heat

• Pain when handled

• Itching, stamping, or chewing

• Lameness in more severe cases

The mistake many owners make is treating the visible scabs without asking why the skin became inflamed in the first place. If the trigger remains, the scabs often return.

Why Do Horses Get Scratches?

Scratches usually starts when the skin barrier is damaged or irritated. Once the skin is weakened, infection, parasites, moisture, friction, allergens, or sunlight can worsen the inflammation.

Common triggers include:

UC Davis lists environmental factors, allergies, drug reactions, fungi, bacteria, parasites, sunlight-induced vascular changes, and extended moisture exposure as potential causes or perpetuating factors. Purdue also highlights wet or dirty environments, damp pastures, wet stalls, and repeated wetting and drying as common contributors. (Centre for Equine Health)

Why Feathered Breeds Are Harder To Treat

Draft horses and heavily feathered breeds are especially prone to scratches because long lower-leg hair traps moisture and debris against the skin. UC Davis notes that pastern dermatitis is most common in draft breeds and horses with heavy lower-leg feathering, and Purdue notes that horses with long leg hair or feathers may benefit from clipping so moisture and contaminants are not trapped against the skin. (Centre for Equine Health)

This is why breeds such as Clydesdales, Shires, Friesians, Gypsy Vanners, and other feathered horses often need more careful leg management.

Feathers are not the enemy. Hidden wet skin under feathers is the enemy. Very glamorous, very inconvenient.

How Serious Are Scratches?

Scratches ranges from mild to severe. The key is whether the skin is dry and comfortable, or swollen, painful, infected, and causing lameness.

A few dry scabs are one situation. A hot, swollen, painful lower leg is another entirely.

What Else Can Look Like Scratches?

Not every scabby pastern is simple mud fever. This is where proper veterinary reasoning matters.

Important rule-outs include:

Bacterial pastern dermatitis

Bacteria often move in once the skin barrier is damaged. This is more likely if the skin is wet, swollen, painful, oozing, smelly, or producing yellow or white discharge.

Fungal infection

Fungal disease can cause scaling, crusting, hair loss, and poor response to antibacterial treatment. It may spread through shared brushes, rugs, tack, or direct contact.

Chorioptic mange

Chorioptic mange is caused by Chorioptes mites and is the most common form of mange in horses. MSD notes that it commonly affects draft horses, although any breed can be affected, and signs include itching around the distal limbs, crusting, hair loss, thickened skin, stamping, and rubbing one leg against the other. It is also a differential diagnosis for greasy heel in draft horses. (MSD Veterinary Manual)

Photosensitivity

White or unpigmented legs can develop sun-related skin inflammation, especially when combined with plant exposure, liver disease, or immune-mediated skin disease.

Contact dermatitis

Boots, wraps, bedding, shampoos, sprays, topical medications, pasture plants, or irritating chemicals can all damage the pastern skin.

Pastern leukocytoclastic vasculitis

This is an immune-mediated condition that can affect the lower limbs, often involving white skin and sunlight. It may look like recurring pastern dermatitis but needs a different plan.

Chronic progressive lymphedema

This is especially important in draft breeds, Friesians, and Gypsy Vanners. UC Davis describes chronic progressive lymphedema as a condition involving progressive lower-leg swelling, skin folds, nodules, ulcerations, and recurrent secondary bacterial or parasitic pastern dermatitis. (Horse Report)

If scratches keeps returning, the question should not be, “What cream should I try next?” It should be, “What underlying cause have we missed?”

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 calling a veterinarian if scratches is not responding to treatment, or if there is severe lameness, deep wounds, swelling, excessive heat, or white/yellow discharge. (Purdue Vet School)

How Vets Diagnose Scratches

A vet will usually start with the history and pattern.

Important questions include:

• Which legs are affected?

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

• Is the horse itchy, painful, or lame?

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

• Does the horse have white legs?

• Does the horse have heavy feathers?

• Is this seasonal?

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

• Have flies, mosquitoes, or midges been a problem?

• What products have already been used?

• Are other horses affected?

• Has this happened before?

Depending on the case, diagnostic tests may include:

• Skin scraping for mites

• Tape test

• Hair plucks

• Cytology to check 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 to rule out ectoparasites such as Chorioptes mites, and radiographs to help rule out other causes of lameness. (Centre for Equine Health)

What Should You Do Right Now?

1. Inspect the skin properly

Part the hair and look at the skin itself, not just the outside of the coat.

Look for:

• Redness

• Scabs

• Crusts

• Moisture

• Oozing

• Swelling

• Heat

• Pain

• Hair loss

• 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. Purdue describes a dry, clean environment as the primary defence that allows healing, and recommends keeping affected horses off wet pastures and in a clean, dry stall when needed. (Purdue Vet School)

Practical steps include:

• Avoid deep mud

• Use clean, dry bedding

• Fill muddy areas around gates and water troughs

• Dry legs before stabling

• Avoid repeated wetting and drying

• Keep the pastern area as dry as practical

If the horse is treated perfectly but still stands in wet mud every day, the skin has very little chance to recover.

3. Clip long hair if needed

Clipping is often helpful, especially in horses with heavy feathers or matted hair. It allows you to see the lesions, dry the skin, apply treatment properly, and monitor healing.

Purdue recommends carefully clipping hair away from the infected area while avoiding scraping or breaking the skin. (Purdue Vet School)

For heavily feathered horses, clipping can feel like sacrilege. In recurring or painful cases, it is often the difference between treating the skin and treating the outer layer of hair.

4. Clean gently

Gentle cleaning can help, but harsh scrubbing makes scratches worse.

Your vet may recommend an antibacterial shampoo such as chlorhexidine, povidone-iodine, or benzoyl peroxide, or an antifungal shampoo such as miconazole depending on the suspected cause. Purdue advises letting medicated shampoo sit for about 10 minutes before gently rinsing, and avoiding rough scrubbing and harsh chemicals. (Purdue Vet School)

The goal is to soften debris and reduce contamination, not scrub the pastern into submission.

5. Do not rip off scabs

Scabs can be very painful and may cover raw tissue underneath.

If scabs need to be removed, they should be softened first and removed gently. Do not pull, pick, scrape, or force them off. Purdue advises that scabs can be carefully massaged off after softening, but should not be pulled or picked. (Purdue Vet School)

If the horse is too painful to handle safely, stop and call your vet.

6. Dry thoroughly

This step matters as much as washing.

After cleaning, 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 a classic reason scratches drags on for weeks.

7. Apply medication only as directed

The correct topical treatment 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

Purdue notes that veterinary-recommended ointments may include antibiotics, antifungals, steroids, and other medications, and that systemic antibiotics may be needed in more serious cases. (Purdue Vet School)

Do not layer five random 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 medication 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 advises not using wraps or boots that retain moisture around infected areas. (Centre for Equine Health)

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

Common Treatment Mistakes

Treating every case as mud fever

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

Pulling scabs off dry

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

Over-washing

Washing can help, but constant washing keeps the skin wet. Drying is just as important.

Using harsh chemicals

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 condition.

Ignoring mites in feathered horses

A draft or cob-type horse that stamps, chews, rubs, and keeps relapsing should be checked for Chorioptes 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

Prevention is about protecting the skin barrier and reducing the triggers that damage it.

Useful prevention steps include:

• Check pasterns regularly during grooming

• Keep legs as dry as practical

• Avoid prolonged turnout in deep mud

• Fill muddy gateways and areas around 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, drying pasterns well after bathing, keeping lower-leg hair clipped when needed, avoiding long-term moisture-trapping boots and wraps, and maintaining clean, dry bedding. Purdue similarly recommends dry footing, dry bedding, drying legs before stabling, avoiding moisture-retaining boots or wraps, and checking legs frequently for early signs. (Centre for Equine Health)

Will My Horse Recover?

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

The best outcomes happen when:

• The case 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 changed, not just the cream

• 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. It also notes that secondary bacterial infections are common and can complicate diagnosis, treatment, and recovery. (Centre for Equine Health)

Chronic cases can take longer, especially in heavily feathered horses or horses with chronic progressive lymphedema. In those cases, 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.

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.

Are scratches contagious?

Some causes can spread, especially mites and fungal infections such as ringworm. If more than one horse is affected, or if grooming tools, boots, or rugs are shared, ask your vet about biosecurity and testing.

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 are only the visible part of the problem. Underneath, there may be moisture damage, bacterial infection, fungal disease, mites, insect irritation, sunlight sensitivity, contact dermatitis, or chronic lower-leg disease.

The most effective 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 is what 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.