Horse skin and lower-leg care
Scratches in Horses: Pastern Dermatitis Guide
Scratches, mud fever, greasy heel, and dew poisoning are common names for equine pastern dermatitis: inflammation affecting the skin around the pastern and heel. The name describes where the problem appears, not one single cause. A safe plan starts with drying the area, documenting what you see, avoiding aggressive home treatment, and involving your veterinarian when the case is painful, spreading, swollen, recurring, or slow to improve.
Call your veterinarian promptly if the horse has marked heat or swelling, significant pain or lameness, rapid spread, deep cracks, pus, foul odor, fever, a swollen limb, dark or dying-looking tissue, or a case that repeatedly returns. A hot, enlarging leg or a horse that will not bear weight is not a “wait and see” skin problem.
The practical first move: get the horse onto clean, dry footing; photograph both pasterns; gently remove loose surface mud without scrubbing; dry the skin completely; and stop piling products onto an undiagnosed lesion. Moisture control helps, but it does not replace diagnosis.
What scratches can look like
Early pastern dermatitis can be easy to miss under mud, long feathering, boots, or wraps. Check the heels, fetlock folds, and the entire circumference of the lower leg—not only the most obvious white marking.
- Pink or red skin, scaling, dandruff-like flakes, or matted hair
- Crusts, scabs, weeping areas, shallow cracks, or thickened skin
- Heat, swelling, tenderness, itching, stamping, or reluctance to let the leg be handled
- Lameness or stiffness when painful cracks sit in a flexing area
- Recurring lesions in the same location after wet turnout, washing, boot use, or seasonal change
White or unpigmented pasterns deserve a careful look, but pigment alone does not diagnose the cause. Severe sun-associated inflammation can resemble ordinary scratches. Review the separate sunburn and photosensitization guide when white legs develop dramatic redness, blistering, sloughing, or lesions beyond the usual mud-contact zone.
What to do in the first 30–60 minutes
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Move to clean, dry footing. Remove the horse from standing mud, wet bedding, saturated grass, or contaminated wash-rack runoff.
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Record the baseline. Photograph both legs in good light. Note heat, swelling, pain, lameness, drainage, odor, and the horse’s temperature if you can take it safely.
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Remove only loose surface contamination. Brush away dry dirt or rinse loose mud when necessary. Do not grind at attached crusts or repeatedly scrub inflamed skin.
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Dry thoroughly. Pat with a clean towel and allow airflow. Do not seal damp skin beneath a boot, bandage, thick coating, or dirty feathering.
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Pause irritants and product stacking. Stop any newly introduced wash, spray, boot, wrap, detergent, or topical product until the trigger is clearer. Do not layer several remedies and then guess which one helped or worsened the skin.
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Escalate based on severity. Contact your veterinarian for red flags, recurrence, substantial pain, spreading lesions, or failure to improve. Keep a farrier involved when hoof balance, heel conformation, cracks, or chronic lower-leg moisture are contributing.
Why the diagnosis matters
Equine pastern dermatitis is a clinical pattern, not a single disease. Wet skin can weaken the barrier and make irritation or secondary infection more likely, but moisture is often only part of the story. A veterinarian may need to distinguish among several contributors:
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Environmental maceration and trauma: repeated wet-to-dry cycles, mud, sand, abrasive footing, clipping irritation, or friction from boots and wraps.
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Secondary microbial involvement: bacterial or fungal organisms can take advantage of damaged skin. Appearance alone does not reliably identify which organism is present.
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Mites or parasites: feathered breeds may develop intense itching and self-trauma that can be mistaken for a simple wet-weather rash.
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Contact irritation or allergy: detergents, disinfectants, topical ingredients, bedding, plants, or equipment residue can inflame the skin.
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Immune-mediated or sun-associated disease: vasculitis and photosensitization can preferentially affect white pasterns and require a different workup.
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Chronic proliferative change: thick, ridged, wart-like, or repeatedly splitting tissue needs veterinary assessment rather than endless scab treatment.
Because causes differ, one horse’s successful routine is not a universal treatment protocol. Your veterinarian may recommend clipping, sampling, culture, skin scraping, biopsy, cleansing, topical medication, systemic medication, pain control, or environmental changes based on the individual case.
What the rider sees—and the next decision
| Observation |
Practical next step |
| Mild pinkness or scaling after wet turnout, with no heat, swelling, pain, or lameness |
Move to dry footing, photograph, gently clean only as needed, dry completely, and monitor closely. Seek veterinary guidance if it persists or progresses. |
| Crusts, weeping skin, painful cracks, or recurring lesions |
Arrange a veterinary evaluation before repeatedly changing products. Recurrence is evidence that the underlying contributor has not been controlled. |
| Hot, swollen lower leg; marked tenderness; spreading redness; fever; or lameness |
Call the veterinarian promptly. Deeper infection or cellulitis can require more than topical care. |
| Intense itching, stamping, rubbing, or heavy feathering |
Ask the veterinarian to consider mites and other itch-producing causes. Avoid assuming the problem is only mud. |
| White pasterns with blistering, sloughing, severe sun sensitivity, jaundice, dark urine, or illness |
Move out of sunlight and contact the veterinarian. Photosensitization or systemic disease must be considered. |
| Thick, ridged, wart-like, blackened, or nonhealing tissue |
Stop routine home treatment and obtain veterinary assessment; sampling or biopsy may be needed. |
What not to do
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Do not forcefully pick attached scabs. Removing firmly attached crusts can tear living tissue and increase pain.
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Do not repeatedly scrub with harsh cleansers. More cleaning is not automatically better when the skin barrier is already damaged.
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Do not trap moisture. Occlusive boots, wraps, heavy coatings, and dirty feathering can keep the area warm and damp.
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Do not use caustic or improvised remedies. Bleach, concentrated disinfectants, livestock dewormers, essential-oil concentrates, and human medications can injure skin or complicate diagnosis.
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Do not put liniment into open cracks or weeping lesions. A liniment is not a treatment for pastern dermatitis, infection, vasculitis, mites, or photosensitization.
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Do not return to wet turnout just because the surface looks cleaner. Protecting the healing skin from the same exposure is part of the plan.
Reducing wet-weather recurrence
Prevention is less about one miracle product and more about controlling the conditions that repeatedly compromise the skin.
- Improve drainage around gates, feeders, waterers, shelters, and high-traffic lanes.
- Provide clean, dry standing areas and replace saturated bedding promptly.
- When practical, delay turnout until heavy dew has lifted rather than sending a susceptible horse through soaked grass at daybreak.
- Rinse only when needed and dry the pasterns fully after washing, icing, or wet work.
- Clean and dry bell boots, brushing boots, wraps, towels, and grooming tools between uses.
- Check beneath feathering and equipment every day; early pinkness is easier to address than painful cracking and swelling.
- Review clipping, detergents, sprays, bedding, footing, and pasture changes when a flare follows a new exposure.
- Keep farrier intervals and hoof balance consistent so chronic heel stress and deep creases do not compound the moisture problem.
Build a recurrence log. Record weather, dew or mud exposure, turnout duration, wash products, boots or wraps, clipping, affected legs, photos, temperature, treatment directed by your veterinarian, and time to improvement. Patterns often become clearer when the details are written down.
Related Draw It Out® horse-care resources
Frequently asked questions
Are scratches, mud fever, greasy heel, and dew poisoning the same thing?
These names are commonly used for equine pastern dermatitis, a pattern of inflammation affecting the lower leg. They do not identify one single cause, so persistent, painful, spreading, or recurring cases need veterinary evaluation.
Should I pick the scabs off a horse with scratches?
Do not forcefully pick or scrub attached crusts. That can tear painful skin and worsen inflammation. Follow your veterinarian’s instructions for any clipping, cleansing, softening, or crust removal.
Can I wrap a horse’s pastern when it has scratches?
A wrap can trap moisture, heat, drainage, or topical residue against damaged skin. Do not bandage an affected pastern unless your veterinarian has given a specific plan and you can keep the materials clean and dry.
Is dew itself what causes dew poisoning?
Dew is not a poison. Wet grass and prolonged moisture can soften the skin barrier and create conditions that favor irritation and secondary infection. The underlying cause can differ from horse to horse.
When should I call the veterinarian for pastern dermatitis?
Call promptly for marked swelling, heat, pain, lameness, rapid spread, deep cracks, pus, foul odor, fever, a swollen limb, dark or dying-looking tissue, or a case that keeps returning or does not improve.
How can I reduce recurring scratches?
Improve drainage and dry footing, wait for heavy dew to lift when practical, dry pasterns after washing or wet turnout, clean and dry boots and wraps, check the legs daily, and work with your veterinarian or farrier on horse-specific contributors.
Reviewed and updated July 29, 2026. This guide is educational and does not replace examination, diagnosis, or treatment by your veterinarian.
