Rain, Mud, and Scabby Legs: How to Outsmart Mud Fever This Winter

If you’ve owned horses through a wet winter, you’ve probably come across the dreaded mud fever. As if riding in the rain and dealing with muddy, soggy fields isn’t enough, skin issues can feel like the final straw.

But what actually causes mud fever, and what can we do about it? Let’s break it down in simple terms.

What Is Mud Fever in Horses?

Mud fever, also known as pastern dermatitis or greasy heel, is a skin condition that typically affects the lower legs. When the skin is constantly wet or muddy, bacteria and fungi can invade, causing scabs, hair loss, and soreness. Horses with white legs or sensitive skin are often more prone to this condition.

What causes Mud Fever?

The ultimate culprits are bacteria, fungi, and mites that thrive in damp environments and invade weakened skin.  But some skin is more vulnerable than others, with risk factors including:

• Prolonged exposure to wet and muddy fields – constant moisture leads to cracked and softened skin.
• White legs and pink skin – horses with lighter skin are more prone to mud fever and other horse leg skin infections.
• Cold weather – reduces circulation and slows healing, making infections worse.
• Cuts or abrasions – even small nicks provide an entry point for bacteria.

Myth Buster- 'Mud fever only happens in wet weather'.

Reality: While wet and muddy conditions increase the risk, mud fever can also develop in seemingly dry conditions if there’s dirt, manure, or damp bedding that irritates the horse’s skin. Poor hygiene, weak immunity, and minor skin injuries can all contribute, even when it hasn’t rained recently.

Symptoms of Mud Fever

The symptoms of mud fever can range from mild scabbing to painful swelling that affects movement. Early detection is key.

Look for:

• Lumps and bumps (tiny scabs) on the legs – usually starting around the pasterns or fetlocks.  Run your hand up and down the leg to feel them.
• Hair loss and raw skin – as the infection develops, the hair often falls out, leaving sore patches.
• Heat and swelling – inflamed skin may feel hot to the touch when you run your hand over the leg, and the legs can swell.
• Pain and sensitivity – your horse may react when you touch the affected area.
• Lameness – in severe cases, mud fever can make horses reluctant to move, raising concerns about whether mud fever causes lameness in horses. (answer: yes, it can).

Guarding Against Mud Fever – What We Do at Biteback

Prevention is better than cure. We follow this regime on our herds of field-dwellers:

1. Check legs daily, paying close attention to pasterns and fetlocks. Early detection is key. Catching scabs, hair loss, or swelling early allows for prompt defensive action.
2. Rotate paddocks, provide dry turnout areas, or use a stable during very wet conditions to reduce constant contact with mud.
3. Very gentle cleaning: Avoid washing and brushing of vulnerable skin. Instead, let the mud dry and remove it with fingers or a rubber curry comb. Avoid washing the legs: the wet and cold conditions will only exacerbate the issue. Instead, gently cleanse the area with a mild antiseptic lotion such as Quick-Silver. Spray onto the affected area, gently massage it into the skin, and wipe away any excess with a clean towel.
4. Dry, dry, dry – Moisture is the enemy here, so always gently pat dry with a clean towel, and puff on a drying powder, massaging it into the skin. Flowers and Zinc Antiseptic Powder will absorb excess moisture, and it is naturally antiseptic and antibacterial. A dry surface will also help any creams adhere to the skin.
5. Soften scabs – Use a soothing cream to help any scabs come away naturally. Mudbar Plus is moisturising and the Ionic Silver will support the skin's natural healing.
6. Protect the skin – Apply a waterproof barrier cream to keep mud and moisture out. Mudbar Plus cream forms an antiseptic shield, blocking the entry of microbes and other environmental irritants. It is highly water-resistant, providing long-lasting support for the skin's natural barrier.
7. Maintain strong overall skin health – A balanced diet rich in vitamins and minerals supports the skin’s natural defenses. Healthy skin is less prone to wet-weather horse skin problems.
8. Call your vet if you are worried – If it seems to be taking hold, antibiotics may be needed.

Tips for Faster Healing

• Keep your horse stabled or on hard standing for a period after applying products, to allow them to absorb into the skin.
• Check legs daily for new scabs or irritation.
• Avoid turnout in muddy paddocks until there is visible improvement (not always possible depending on your set-up)

By combining these mud fever prevention strategies, you can significantly reduce the risk and keep your horse comfortable and active—even in the wettest seasons.

Managing a Full-Blown Infection – What We Do at Biteback

"My mare came back from an equine maternity yard with the start of Mud Fever. I think there were 2 reasons why she'd developed it: Firstly, she lost fitness and condition because of foaling and was more susceptible to infections, and secondly, she was in a much smaller space so did a lot less walking around and her legs had started to fill." - Kath Shaw, Biteback founder

A severe infection will typically appear as widespread scabby lesions clearly visible around the joint, often accompanied by bloody inflammation between the scabs. The affected legs will be tender to the touch and may swell with fluid above the joints. The horse is also likely to show signs of discomfort or altered behaviour.

If the scabs are thick and firmly attached, wrap the joint overnight with cling film and a layer of vet wrap after completing the preventative steps outlined above. When possible, turn the horse out to help reduce swelling. The following morning, remove the cling film, repeat the preventative care, and leave the legs unwrapped during the day. Continue re-wrapping overnight until most of the hard, crusted scabs have softened and fallen away.

If there is no noticeable improvement within 3–4 days, contact your veterinarian. Your horse may require an oral antibiotic and/or a short course of steroids to encourage healing. Always seek veterinary advice if you are unsure about the condition or its management.

Mud Fever FAQs

1. What causes mud fever in horses?
Bacteria and fungi invade weakened skin, usually after prolonged wet and muddy conditions.

2. Is mud fever contagious?
Not directly, but bacteria can be present in shared muddy areas. Good hygiene helps reduce risk.

3. Can mud fever cause lameness?
Yes. Severe cases can make horses uncomfortable or reluctant to move.

4. What is the best way to treat mud fever?
Gently clean, dry, and apply a barrier or medicated cream. Call a vet for persistent or severe cases.

5. How can I prevent mud fever in winter?
Check legs daily, reduce mud exposure if it’s possible, use barrier products if horse is prone.

6. Do horses with white legs get mud fever more often?
Yes, lighter skin is thinner and more susceptible.

7. Can I ride my horse with mud fever?
Light riding may be okay for mild cases, but avoid riding if there’s swelling, pain, or lameness.

8. Should I wash the mud off the legs?

No, avoid washing as the cold and excess moisture can make matters worse.