Mud fever is a skin inflammation in the fold behind the fetlock, usually caused by a combination of moisture, mud, and bacteria. You'll recognize the scabs quickly; getting rid of them again mainly takes patience and a dry environment.
What Mud Fever Is and How to Recognize It
Mud fever — also called scratches — is usually found in the pastern: the fold at the back of the lower leg, just above the hoof. The skin becomes inflamed there, starts to flake, and forms scabs. Under the scab, the skin is often moist and raw.
Common signs:
- Scabs, flaking, or bald patches low on the leg
- A thick, sometimes warm lower leg
- Sensitivity to touch; some horses pull the leg away
- In a more serious stage: lameness or a heavily swollen leg
Mud fever occurs most in the wet season — fall, winter, early spring — when legs stay wet and muddy for long periods. Horses with white leg markings seem more prone to it, because the pink skin underneath is more vulnerable. Horses with a lot of feathering (such as Friesians and Gypsy Cobs) are also susceptible, because the hair holds moisture and dirt against the skin; in these breeds, the chronic form is sometimes also called mauke.
First, Remove the Cause
Treatment has little effect as long as the legs stay wet and dirty. The core of the approach is simple: get the skin dry and keep it dry.
- Get the horse out of wet, muddy conditions where you can. A dry stable floor or a drier paddock often helps more than any ointment.
- Clean the leg thoroughly once and then dry it thoroughly, especially in the fold. After that, get it wet as little as possible — repeated washing softens the skin and keeps the problem going.
- For horses with a lot of feathering: trim the hair around the affected area short, so air can reach it and you can see the skin.
- Manure and bedding residue against the legs make it worse. A clean, dry place to lie down is part of the treatment.
Caring for the Scab and the Skin
Once the environment is under control, you turn your attention to the skin itself. The usual approach focuses on gently loosening the scab and keeping the skin underneath dry and protected.
| Step | Approach |
|---|---|
| Loosening the scab | Soften it a little if needed so the scab comes away without tearing the skin open — don't pick at it roughly |
| Cleaning | Gently clean the skin underneath and pat it thoroughly dry |
| Protecting | A drying or protective ointment (often zinc-based) keeps moisture out |
| Giving rest | Leave it alone afterward; don't scrub it again every day |
Which product suits best depends on how severe and how extensive the mud fever is. Ask your vet or an experienced stable keeper for concrete advice for your horse, rather than experimenting with strong products yourself. Don't mix up your own remedies: aggressive products can further irritate skin that's already damaged.
When to Call the Vet
Mild mud fever often clears up with dryness and care within a few weeks. Bring in the vet if:
- the leg becomes noticeably thick, warm, or painful
- the horse is lame or seems to have a fever
- pus or a bad smell appears
- it doesn't improve, or actually spreads, after a few weeks of consistent care
- the mud fever keeps coming back despite dry conditions
The vet can assess whether a bacterial infection, fungus, or mite is behind it and whether additional treatment is needed. Using antibiotics or other prescription medication yourself is not a good idea — always leave the dosage and choice to the vet. When in doubt: better to call once too early than to let an inflammation go deeper.
Preventing It From Coming Back
Mud fever is notorious for returning readily in a wet stable or muddy paddock. Prevention is mainly about the daily routine:
- Keep the legs as dry as possible. A dry place to lie down and, where possible, a drier turnout area do most of the work.
- Check the pasterns regularly, especially in the wet season. Early action saves weeks of treatment.
- Don't wash the legs unnecessarily. Letting mud dry and brushing it off is usually better for the skin than hosing it down daily.
- Trim feathering short on susceptible horses, so the skin can dry and you spot problems early.
- Watch white legs. The more sensitive skin there deserves extra attention and protection during the wet months.
A regular grooming routine in which you check the lower legs is the cheapest prevention there is.
In Short
Mud fever develops where moisture, dirt, and bacteria come together on vulnerable skin. Treatment doesn't start with the ointment but with the environment: get the legs dry and keep them dry. Care for the scab gently, use a drying or protective ointment, and let the skin rest. If it doesn't improve, the leg becomes thick or painful, or the mud fever keeps coming back, bring in the vet. For the exact choice of product and any medication, the vet is the right source.
See also: Glossary: mud fever · Daily Horse Care: The Basic Routine · Level: Considering Your Own Horse