Mud fever is one of the most common skin conditions in horses and primarily affects the sensitive skin in the pastern area. The good news is that with the right care, mud fever can be effectively treated and prevented. In this guide, you’ll learn everything about the causes, symptoms, and different severity levels of mud fever, as well as how you can help your horse with the appropriate treatment.
What is mud fever in horses?
mud fever is an inflammatory skin disease that often occurs in the fetlock area of horses. It is caused by a combination of moisture, dirt and bacteria or even mites and manifests itself as redness, swelling, crusting and weeping wounds.
Horses with long fetlocks are frequently affected, especially in the winter months. The disease occurs quite frequently and is considered difficult to treat if severe, as therapy is often laborious and takes a long time. If left untreated, mud fever can lead to pain and restricted movement.
Important to know: Mud fever is not a single disease, but a complex of symptoms with various possible causes. Depending on the trigger and severity, different forms of mud fever are distinguished—ranging from mild skin irritation to chronic warty mud fever.
Forms of mud fever: From mild to chronic
Mange can occur in varying degrees of severity. It is important to distinguish between these degrees, as they influence treatment:
Mild mud fever
The skin in the pastern area shows initial redness, slight flaking, and fine cracks. The horse is sensitive to touch. At this stage, mud fever is usually easy to treat and heals completely with consistent care.
Exudative (weeping) mud fever
The skin is severely reddened, weeping, and forming yellowish scabs. Wound fluid accumulates under the scabs, providing an environment where bacteria can continue to multiply. The horse shows clear signs of pain. This condition requires careful, gentle treatment.
Chronic mud fever (warty mud fever/rasp)
In cases of prolonged or recurring mud fever, the skin can undergo permanent changes. Wart-like growths and thickened areas of skin form—a condition known as warty mud fever or raspe. This chronic form spreads upward from the fetlock toward the cannon bone. It requires long-term, intensive care.
Causes of mud fever in horses
It is almost impossible to keep the skin in the fetlock free of germs. Normally, germs are repelled by the skin's natural protective barrier and by the immune system when they enter.
However, the skin in the fetlock is under a lot of strain as it is exposed to constant movement and stretching. Tiny injuries, such as small tears in the fetlock bend, are the gateway for germs and mites to enter the skin. Insect bites can also severely irritate the skin and promote mud fever. The sparse hair also makes it easier for germs to reach the skin.
Once they have reached the uppermost layer of the skin (epidermis), they can spread further. The body reacts to this with an inflammatory reaction. A mixture of wound fluid, dead skin flakes, dirt from the environment and the germs causing the infection then results in the typical crust of the scab, which sticks very firmly to the skin and hair. Under the crust, the germs can continue to multiply in the moist, warm environment and attack new, still healthy skin. This creates a vicious circle in which ever larger crusts and more severe inflammation can develop.
Mud fever can also be caused by a long-standing foot rot in which the bacteria spread from the frog, across the sole, all the way to the pastern!
Sorrels and horses with light skin in particular are affected more frequently and more severely than horses with dark skin.
Other risk factors for mud fever:
- Breed predisposition: Cold-blooded breeds, Tinkers, and Friesians, with their thick fetlock hair, are particularly susceptible. The thick hair keeps moisture against the skin longer and makes it harder for the horse to dry off.
- Mite infestation: Chorioptes mites (foot scabies mites) can cause or worsen mud fever.
- Photosensitivity: Horses with unpigmented (pink) skin and white legs are more sensitive to UV radiation. Irritated skin is more susceptible to infection, so mud fever can occur even in the summer.
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Environmental factors: Muddy paddocks, wet bedding, sand, and irritating plants (e.g., stinging nettles) significantly increase the risk of mud fever.
Recognizing Mud Fever in Horses: Symptoms and Stages
Small rednesses, which are usually not taken too seriously, are often the start of a mud fever. A few hours to days later, small crusts may cover the skin. These then quickly become larger and protrude more and more from the healthy skin.
Sometimes the areas ooze and are very red. In this case, these areas hurt the horse and can lead to serious, difficult-to-treat skin inflammation or even phlegmon.
An Overview of Typical Signs of Mud Fever
- Redness and swelling in the pastern
- Flaky, cracked skin
- Crust formation (yellowish-brown, firmly adhering)
- Weeping areas under the scabs
- Sensitivity and pain response to touch
- Heat to the affected area
- In severe cases: lameness and swelling of the entire leg
The sooner you recognize the first signs and take action, the better the chances of recovery. Therefore, check your horse’s pasterns regularly—especially during the wet season and in horses with fetlocks.
When should you consult a veterinarian?
In many cases, early-stage mud fever can be treated at home with consistent care. However, there are situations in which you should consult a veterinarian:
- Severe swelling of the entire leg (may indicate phlegmon)
- Lameness or significant restriction of movement
- Fever or general lethargy in the horse
- Pus-like discharge or a strong odor
- No improvement despite consistent treatment after 1–2 weeks
- Suspected mite infestation (severe itching; the horse is stamping or rubbing itself)
- Chronic or recurrent mud fever that does not improve permanently
- Bleeding areas of skin
The veterinarian can determine the exact cause (e.g., through a swab or a hair sample) and, if necessary, initiate targeted treatment—such as for mites, fungal infections, or bacterial infections.
Preventing mud fever in horses
In order to prevent mud fever, it is important to keep the skin of the fetlock bend clean and supple. If the skin is cared for and small wounds are cleaned immediately with a disinfectant soap, it is difficult for the germs that cause mud fever to penetrate the skin. Hygiene in the stable and exercise area reduces the bacterial load in the fetlock bend and is therefore essential to prevent mud fever.
If you detect crusts in the fetlock bend, it is necessary to treat them immediately and not let a few more days pass, as the mud fever can spread very quickly.
Additional preventive measures:
- Paddock Management: Avoid permanent muddy patches. Good drainage, paddock mats, or regular mucking out will keep the ground drier. A paved feeding area can also help.
- Equipment Hygiene: Clean gaiters, bandages, and hoof boots regularly and allow them to dry completely. Damp, dirty equipment promotes the growth of germs directly at the pastern.
- Foreskin Care: For horses with long fetlock hair, regular trimming can help keep the skin dry. Important: Do not shear if the horse has acute mud fever—shearing can further irritate the skin.
- Keep the pastern dry: Always dry the pastern thoroughly after washing or if it gets wet. Residual moisture under the fetlock is an ideal breeding ground for germs.
Good hoof care also helps prevent infections: Healthy hooves and a well-groomed frog prevent germs from spreading from the hoof toward the pastern.
Home Remedies for Mud Fever: What Really Works?
Many horse owners initially turn to home remedies for mud fever. Some of these are quite effective, but others can actually make the situation worse:
- Zinc ointment: Can help soothe the skin in cases of dry, scaly mud fever. However, it is unsuitable for weeping mud fever because it forms an airtight film that traps moisture under the scab. The zinc ointment does not dissolve the scab, so it does not address the underlying cause.
- Curd soap: Is often recommended, but it’s counterproductive. Soaps have an alkaline pH, which promotes the growth of bacteria and fungi—exactly the opposite of what we want to achieve.
- Honey: Does indeed have antibacterial properties and can be helpful for small, superficial wounds. However, it is not sufficient on its own for extensive or weeping mud fever.
- Iodine soap/Betaisodona: Has a disinfecting effect, but dries out the skin significantly. Frequent use can also irritate the skin.
- Ballistol/Oils: Keep the skin supple but have no disinfecting effect. Not sufficient as the sole treatment for acute mud fever. Essential oils can further irritate the skin.
The problem with many home remedies: they only treat the surface, not the underlying cause. For stubborn scabs, you need a solution that gently loosens the scab without damaging the skin underneath—that’s exactly what the Keralit Keralysin Ointment was developed.
Common mistakes in mud fever treatment
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Removing scabs without proper preparation
Whether dry or pre-soaked: Removing scabs without proper preparation damages the underlying skin and allows germs to penetrate new areas of skin. The next day, the scab is back, and the mud fever is even worse.
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Washing the pasterns
Washing a horse’s pasterns when they are heavily soiled is a good idea to thoroughly remove any additional dirt from the already irritated skin.
However, washing them too frequently is counterproductive, as pathogens multiply even faster in damp conditions.
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Wash the fetlock bend with curd soap
Bacteria and fungi love an alkaline environment. Soaps have an alkaline pH value and therefore promote the growth of germs.
Treating Mange: Step-by-Step Care
The proper treatment involves removing the scabs as gently as possible without damaging the underlying skin. A good way to gently remove scabs is the Keralit Keralysin Ointment
. Once the scab can be gently scraped off, the underlying areas can be disinfected or soothed with a nourishing ointment. For skin care and regeneration, use Keralit Dermacure Ointment is ideal for skin care and regeneration. This allows the affected areas to heal and the skin to restore its protective barrier.
The goal of treating mud fever is to gently remove the scabs without damaging the underlying skin—and then to promote skin regeneration.
Step 1: Gently remove the crust
Apply the Keralit Keralysin Ointment generously to the crusted areas. The ointment gently softens the crusts overnight so that they can be removed the next day without damaging the underlying skin.
Step 2: Gently remove the scabs
Once the scabs have softened, you can gently wipe them away with a soft cloth or your fingers. Important: Do not rub or scratch! Scabs that haven’t come off yet need further treatment.
Step 3: Nourish and regenerate the skin
After removing the scabs, the skin needs care to restore its natural protective barrier. The Keralit Dermacure Ointment supports the regeneration of dry and irritated skin and keeps it supple.
Step 4: Continue treatment consistently
Mud fever rarely heals overnight. Repeat the treatment daily until the skin has completely healed. Even after healing, you should continue to monitor the pastern area for a few more days and treat it as needed.
Important: If you suspect a mite infestation, fungal infection, or bacterial involvement, a veterinarian should determine the cause, as additional targeted treatment may be necessary in such cases.
Feeding for Mud Fever: Nutrients That Support the Skin
In addition to external care, diet can also contribute to skin health. Certain nutrients support skin regeneration and strengthen its natural protective barrier:
- Zinc: One of the most important nutrients for skin health. Zinc plays a role in wound healing and strengthens the skin barrier. Horses with recurring skin problems may have a zinc deficiency.
- Biotin: Known for its beneficial effects on hooves and coats, biotin also supports skin regeneration.
- Vitamin A: Promotes cell renewal in the skin and mucous membranes.
- Essential fatty acids: Omega-3 and omega-6 fatty acids (e.g., from flaxseed oil) support healthy skin structure.
A high-quality mineral supplement such as ATCOM Huf-Vital can help fill nutritional gaps and support the skin, hooves, and coat from the inside. However, this supplement does not replace external treatment; rather, it complements it. Mud fever must always be treated topically as well.
Frequently Asked Questions About Mud Fever in Horses
Is mud fever contagious in horses?
Mud fever itself is not directly contagious from horse to horse. However, the pathogens that cause it (bacteria, fungi, mites) can be transmitted through shared equipment such as brushes, leg wraps, or bandages. Therefore, be sure to use separate grooming supplies and clean the equipment regularly.
Should you remove the scabs when a horse has mud fever?
Yes—but only gently! Under the scabs, bacteria continue to multiply in the warm, moist environment. Removing the scabs is therefore important for healing. However, the scabs must never be scraped or torn off, as this damages the skin and worsens the mud fever. A special ointment for gentle scab removal (such as Keralit Keralysin Ointment) is the best solution here.
Can mud fever occur in the summer as well?
Yes, mud fever isn’t just a winter condition. In the summer, insect bites, photosensitivity (especially in horses with white legs), and mite infestations can lead to mud fever. Dry, cracked skin caused by dust and sand can also serve as an entry point for germs.
What is the difference between Mauke and Raspe?
Raspe (also known as warty mud fever) is a chronic form of mud fever. While acute mud fever can heal completely with proper treatment, prolonged or recurrent mud fever leads to permanent skin changes: the skin thickens and forms wart-like growths that spread upward from the fetlock toward the cannon bone. Raspe is particularly common in draft horses andcanoccur even without a history of mud fever, due to genetic predisposition, chronic skin and lymphatic issues, or the horse’s coat and skin condition.
Does shearing help with mud fever?
Trimming the fetlock hair can be a helpful preventive measure, as it allows the skin to dry more easily. However, you should not shear the hair if your horse has acute mud fever: the clippers can injure the irritated skin and worsen the inflammation. Wait until the skin has fully healed before trimming the hair.