Mud Fever in Horses: Causes, Symptoms, Treatment and Prevention

What Is Mud Fever in Horses?

Mud fever in horses is an inflammatory, eczema-like skin condition that affects the pastern area. Since it usually remains limited to this region, it is also referred to as pastern eczema. In veterinary terminology, the condition is also known as superficial dermatitis.

A typical feature of mud fever is that it is not caused by a single trigger alone. Instead, it is considered a multifactorial disease. This means that it usually develops through a combination of factors such as a damaged skin barrier, moisture, germs, friction, metabolic stress, and a weakened immune system.

Horses with dense feathering around the pasterns, such as Tinkers or Friesians, are especially susceptible. Horses with light-colored or poorly pigmented skin in the pastern area also have a higher risk. Although mud fever in horses often occurs during the wet and cold seasons, the weather alone is not the cause. What matters most is whether the skin has already been damaged and how stable the horse’s metabolism and immune system are.

Mud fever can appear very suddenly, but it is often stubborn and persistent. In the worst case, it can even become chronic. That is why treatment must be just as consistent and persistent, with the affected areas being cared for thoroughly and regularly.

Symptoms

Mud fever in horses usually appears on one or more legs in the pastern area. The hind legs are especially often affected, but in principle mud fever can also occur on the front legs.

Typical signs include:

• reddened and irritated skin
• itching
• dry or greasy scabs
• weeping skin lesions
• matted or sticky hair
• hair loss
• swelling
• sensitivity to touch
• pain
• in severe cases, lameness

How Mud Fever Develops

At first, there is often only a slight redness of the upper layer of the skin. Later, small blisters or nodules may form, which then develop into scabs. If these scabs repeatedly crack open through movement, the inflammation can penetrate deeper into the skin.

Without treatment, mud fever can worsen significantly. This may lead to painful fissures, poorly healing skin lesions, and in some cases excess tissue growth or wart-like changes. In the worst case, secondary infections and marked swelling of the leg can occur.

Causes

Mud fever is a multifactorial disease, which means there is not just one single trigger, but rather a combination of different causes that lead to its development. The key factor is that the skin barrier becomes damaged, allowing pathogens to penetrate more easily.

Mechanical Damage to the Skin

Friction caused by poorly fitting hoof boots, leg boots, or bandages can irritate the skin. Fine dirt on the legs can also act like sandpaper under equipment and cause tiny skin injuries. In addition, abrasions, cuts, or scratched insect bites can weaken the skin barrier.

Ammonia from urine and manure can also irritate the skin. That is why regular mucking out is important not only for stable air and the horse’s respiratory tract, but also for maintaining healthy skin.

Bacteria, Fungi, and Mites

If the skin is already damaged, bacteria, fungi, and mites can invade more easily. They may trigger inflammation or worsen existing skin problems.

Mites make the problem even worse because they cause intense itching. The horse rubs and scratches itself, the skin becomes further damaged, and healing is delayed.

Metabolism, Immune System, and Stress

Moisture and mud are often only the external trigger. Whether mud fever in horses actually develops depends largely on how stable the skin barrier, immune system, and metabolism are.

Nutrient deficiencies, an unbalanced diet, stress, or impaired detoxification processes can all increase susceptibility. During the coat change, in particular, the need for minerals rises. If these deficiencies are not compensated for, skin regeneration suffers and mud fever can develop more easily.

Diagnosis

Mud fever can often be identified based on its typical symptoms alone. Even so, it is advisable to consult a veterinarian if the skin changes are severe, weeping, getting worse, or if the horse is showing signs of pain.

The veterinarian can take a swab to identify the pathogens involved. In severe cases, a resistance test can help determine the most appropriate treatment.

Three forms of progression can generally be distinguished:

Mild Mud Fever

Reddened skin, itching, hair loss, and mild pain

Exudative Mud Fever

Weeping lesions, more pronounced scab formation, hair loss, and significant pain

Chronic Mud Fever

Skin overgrowths, thickened skin, and so-called verrucous mud fever

Treating Mud Fever Correctly

Anyone who wants to treat mud fever needs above all patience and consistency. The condition rarely disappears quickly, but with clean and careful management, it can often be brought under control.

• Keep affected areas clean and dry: The affected skin areas should be kept as clean and dry as possible. Dry bedding, regular mucking out, and as little contact with mud as possible all support healing.
• Trim excess feathering: In horses with heavy feathering, it may make sense to carefully trim the hair around the affected area. This allows more air to reach the skin and makes treatment easier.
• Soften scabs carefully: Scabs should never be removed by force. Instead, soften them gently with lukewarm water and a mild cleansing solution.
• Dry the skin thoroughly: After cleaning, the pasterns must be dried carefully. Always use a clean towel so that germs are not spread further.
• Apply suitable skincare: The next step is to use a protective cream to help prevent new cracks and support skin regeneration. For dry, cracked mud fever, nourishing and breathable products are helpful. For weeping lesions, a drying treatment may be more suitable. Very greasy, air-tight creams are not recommended, as they prevent the skin from breathing.
• Involve a veterinarian: If treating mud fever in horses with local care is not enough, or if the inflammation is already severe, a veterinarian should supervise the treatment.

Preventing Mud Fever Properly

Prevention is especially important when it comes to mud fever in horses, because the more stable the skin barrier, metabolism, and immune system are, the lower the risk.

• Hygienic living conditions: Provide dry bedding, a clean and well-drained paddock/turnout area, and daily mucking out / manure removal.
• Clean pasterns and hooves: Especially before using hoof boots, bell boots, fetlock boots, or bandages, make sure the horse’s legs are completely clean. If necessary, rinse the legs with water first, wash them with soap, and dry them thoroughly before putting on any leg or hoof protection. Be just as meticulous about the cleanliness of the legs as you are about the horse’s back before saddling.
• Mineral supply: Make sure the horse gets enough zinc, especially if it is fed mainly hay and/or receives only a small amount of concentrates.
• Avoid stress: Stress reduces the absorption of minerals, increases the horse’s need for them, and also weakens the immune system. Find a management setup in which the horse can live in a relaxed way, prepare well for unusual situations, and try to make them as stress-free as possible, such as a yard move, competition, or feed change.
• Support the metabolism: With a needs-based diet and enough exercise, the metabolism is stimulated, lymph flow is improved, and the removal of waste products is supported.

Nutrition for Mud Fever

Nutrition is an important factor in both the prevention and management of mud fever. Nutrient deficiencies as well as overfeeding are often reflected in the condition of a horse’s skin. That is why you should always look at the horse holistically, together with your veterinarian. Before making major changes to your horse’s feeding plan, a blood test should be used to check for possible deficiencies or abnormalities.

Relieve the Detoxification Organs

The liver and kidneys play a central role in processing and eliminating metabolic waste products. That is why you should focus on a sugar-conscious, protein-conscious, and needs-based diet. Excess weight can also have a negative effect on skin health.

Feed quality is just as important. Dusty, moldy, or otherwise contaminated feed places an additional burden on the body. A high-quality ration is therefore crucial for both the prevention of and support with mud fever in horses.

You should also take a critical look at additives, flavorings, and preservatives. They are often unnecessary for horses and can place extra strain on the metabolism.

Zinc, Selenium, Copper, Biotin, and Vitamin A

These nutrients are involved in skin regeneration, wound healing, and the skin’s natural barrier function. Zinc in particular is often mentioned as a critical nutrient in connection with mud fever. Horses with a thick coat, heavy feathering, or an increased demand during coat change may be especially sensitive to an insufficient supply.

A closer look at the horse’s mineral supply is therefore especially worthwhile in spring and autumn. However, before supplementing specifically, it should first be checked whether a deficiency actually exists.

🎥 Video tip: From zinc to selenium – in this ClipMyHorse.TV Academy video, you will learn which trace elements are particularly important for skin, the immune system, and regeneration, and what to look out for when supporting your horse’s nutritional needs.

A Healthy Gut Flora Against Mud Fever

A horse’s entire metabolism and immune system are closely linked to the balance of its gut flora. The beneficial bacteria in the gut help the horse utilize nutrients and produce important vitamins.

To keep these microorganisms stable, the horse needs enough high-quality forage and a diet that is relatively low in starch. If the gut flora becomes unbalanced, this can affect the entire metabolism and, in turn, the horse’s skin health.

In some cases, targeted support of the gut flora may be beneficial.

Mud Fever in Horses: Summary

Mud fever is a complex, inflammatory skin condition in horses that is encouraged by various factors such as skin damage, bacterial burden, and a weakened immune system. Horses with dense feathering, light-colored skin, as well as those suffering from nutrient deficiencies or kept in wet, unhygienic conditions, are particularly at risk.

Treating mud fever in horses requires patience and consistent care of the affected areas in order to stop the spread of inflammation and prevent it from becoming chronic. At the same time, an adapted diet and good stable management are important to support both the skin and the immune system. With careful prevention and regular health checks, the risks of mud fever can be reduced and the horse’s quality of life can be improved.

Mud Fever: The Most Important Questions and Answers

Can washing too often encourage mud fever?

Yes. Washing too frequently, especially with shampoo, can weaken the skin barrier. You should therefore clean the legs only as often as necessary and dry them thoroughly afterwards.

Does mud fever go away on its own?

Rarely. Mud fever is usually persistent and can become chronic without consistent care.

Is mud fever contagious?

Mud fever is not considered a classic contagious viral infection. However, stable conditions, pathogen pressure, and high stocking density can increase the risk that several horses may be affected.

Do horses feel pain when they have mud fever?

Yes, especially when scabs crack open and deeper layers of skin are affected. In such cases, mud fever in horses can be clearly painful and may even lead to lameness.

What deficiencies are associated with mud fever?

Most commonly, zinc, selenium, copper, biotin, and vitamin A are mentioned. Whether a deficiency is actually present should always be checked individually.