What causes scabs and hair loss on the backs of horses’ legs?
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Read time: 3 minutes
Overview
Scabs and hair loss on the backs of a horse’s legs are often linked to mallenders or sallenders, but there can be other causes too. It usually starts with dry, flaky, thickened or crusty skin, often in the crease behind the knee or hock, and may be made worse by mud, sweat, grooming friction or skin irritation.
The aim is to check the skin carefully, keep the area clean and avoid making it sore while you work out what’s going on.
Things To Check
1. Check exactly where the scabs are. Mallenders usually affect the backs of the knees on the front legs, while sallenders are usually found on the backs of the hocks on the hind legs.
2. Look for other skin changes such as redness, crusting, thickened skin, broken hair, swelling, discharge or heat.
3. Think about whether it gets worse after muddy turnout, sweating, clipping, washing or heavy grooming.
4. Check whether the horse seems sore, resents touch, stamps, or moves differently when the area is handled.
5. Look at the rest of the coat and skin for itchiness, dandruff, rubbing or similar patches elsewhere.
6. Consider whether the horse has recently changed diet, turnout, bedding, soap, shampoos or grooming routine.
7. Check the legs for mud, dried sweat or tack-related rubs that might be irritating the skin.
Common Causes
Mallenders and sallenders are the most common explanation. These are skin changes that usually affect the bend of the leg and can cause dry scabs, scaling and hair loss.
Skin irritation from mud, sweat, clipping, washing or repeated rubbing can look similar and may keep the area sore if it keeps being irritated.
Some horses also develop skin sensitivity, mild dermatitis or a reaction to grooming products, bedding or environmental irritants.
Less commonly, the skin changes may be linked to infection, mites or another underlying skin issue, especially if the area is very inflamed, spreading or not settling.
What To Do
Gently clean the area if it’s dirty, then dry it well. Avoid scrubbing scabs off, because that can make the skin more sore.
Try to keep the skin as free from repeated rubbing, sweat and mud as you can. If the horse is muddy after turnout, remove dirt carefully rather than working it hard into the skin.
Keep a simple note of when it flares up, what the skin looks like and what seems to make it better or worse. That can help you spot a pattern.
If you use grooming products, stick to mild, horse-appropriate options and avoid anything that seems to sting or leave the skin drier.
If the area keeps returning, is getting more scabby, or the horse seems uncomfortable, it’s sensible to ask your vet for advice.
When To Contact A Vet
Contact your vet if the skin is swollen, hot, painful, oozing, spreading, or if your horse is clearly uncomfortable. It’s also worth getting advice if the problem keeps coming back or doesn’t improve with gentle routine care.
Products That May Help
If the skin is dirty, greasy or a bit scurfy, a gentle wash routine may help support day-to-day grooming without over-rubbing the area.
Related Questions
Is mallenders the same as sallenders?
Can mud and sweat make mallenders worse?
When should I ask a vet about crusty skin on my horse’s legs?
Atlas is here to support owners with practical, easy-to-understand guidance. It is not a substitute for professional veterinary advice. If you're concerned about your animal's health, symptoms worsen, or something doesn't feel right, contact your vet.