Mud Fever Symptoms in Horses: How to Spot the Early Signs
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Knowing how to spot mud fever symptoms early can make a real difference to your horse's comfort and recovery time. Mud fever (or pastern dermatitis) often starts with subtle changes that are easy to miss, especially in horses with heavy feathering or dark skin. By the time thick scabs and lameness develop, the condition has usually been building for days or even weeks.
In this guide, we'll walk through the early, moderate and advanced symptoms of mud fever, explain which areas of the leg are most commonly affected, and share what to look for during your daily routine so you can catch the signs before they worsen. If you'd like to learn more about what causes Mud Fever, check out this blog post.Â
What Does Mud Fever Look Like in the Early Stages?
The earliest signs of mud fever are often subtle and easy to overlook. In the initial stages, you might notice the skin on your horse's lower legs, particularly around the pasterns, heels and fetlocks, looking slightly pink, warm to the touch, or mildly swollen. The hair in the affected area may appear matted or raised, and the skin might feel slightly rough or crusty when you run your fingers over it.
At this point, many owners assume it's just a bit of mud rash or dry skin. But these early signs are your best opportunity to step in with supportive care before the condition progresses.
What Are the Most Common Mud Fever Symptoms?
Mud fever symptoms typically develop in stages. Recognising where your horse sits on this progression helps you respond appropriately.
Redness and Warmth
One of the first noticeable signs is redness or pinkness on the skin of the lower legs. The area may feel warmer than surrounding skin when touched. This is particularly visible on horses with white or pink skin, but can be harder to detect on pigmented legs â which is why running your hands over the legs daily is so important.
Crusty or Flaky Skin
As the condition develops, small crusty patches or flakes may appear. The skin feels rough and scaly, and you might notice fine scabs starting to form. At this stage, the skin barrier is already compromised, and bacteria or fungi are beginning to take hold.
Scab Formation
Scabs are one of the hallmark symptoms of mud fever. They range from small, isolated patches to larger areas of thick, matted crusting. The scabs often bind tightly to the skin and hair, and removing them can be painful for the horse. Beneath the scabs, the skin is typically raw, moist and inflamed.
Swelling in the Lower Legs
As the infection progresses, you may notice swelling (sometimes called "stocking up") in the affected legs. Mild puffiness around the pastern is common in moderate cases. More significant swelling that extends up the cannon bone suggests a deeper infection and warrants closer attention.
Soreness and Sensitivity to Touch
Horses with mud fever often become sensitive when their legs are handled. They may flinch, lift or pull their leg away when you try to brush, examine or clean the affected area. This sensitivity is a clear indicator that the skin is sore and inflamed.
Hair Loss and Matting
In affected areas, the hair may become matted, clumped or start to fall out. You might notice patches where the coat has thinned or where bare, irritated skin is visible beneath the hair. In horses with heavy feathering, the hair can mask these changes, so regular hands-on checks are essential.
Cracked Heels
When mud fever specifically affects the heel bulbs and the back of the pastern, it's often called "cracked heels." The skin in this area becomes deeply cracked, sore and sometimes bleeds. Because the heels flex with every step, cracked heels can be particularly uncomfortable and slow to improve without consistent, targeted care.
Where on the Leg Does Mud Fever Appear?
Mud fever most commonly affects the lower limbs, particularly the pastern area (between the hoof and the fetlock), the heel bulbs, the back of the fetlock, and the front of the cannon bone in more advanced cases.
Hind legs tend to be affected more frequently than front legs, partly because they're more exposed to kicked-up mud and moisture. However, any leg can be affected, and it's not unusual for multiple legs to develop symptoms at the same time.
Can Mud Fever Affect Other Areas?
While the lower legs are the classic location, mud fever can sometimes spread upward or affect other parts of the body. In severe cases, the infection can extend up the cannon bone. A related condition sometimes called "rain scald", affects the back, rump and shoulders, and is caused by the same organism (Dermatophilus congolensis) under similar wet conditions.
If you notice scabbing or soreness on your horse's body as well as the legs, it's worth considering whether rain scald is also present, as the two often go hand in hand during prolonged wet weather.
How Do You Check for Mud Fever?
The best way to catch mud fever early is to make a quick leg check part of your daily routine. Here's a simple approach that takes just a couple of minutes.
Run your hands slowly down each leg from the knee or hock to the hoof, paying particular attention to the pasterns, heels and fetlocks. Feel for any roughness, warmth, swelling or crusty patches. On horses with heavy feathering, part the hair and look at the skin beneath. Lift each foot and inspect the heel bulbs and the back of the pastern. Note any flinching, sensitivity or signs that your horse is uncomfortable being handled on a particular leg.
Doing this consistently means you'll notice changes early, often before visible scabs or lameness develop.
What Should You Do If You Spot Symptoms?
If you catch mud fever in the early stages; mild redness, slight roughness, a few small flakes, gentle, consistent care can help support the skin before the condition worsens.
Keep the legs clean and, crucially, dry. Avoid over-washing, which can strip the skin's natural oils and make things worse. If you do need to clean the legs, dry them thoroughly afterwards.
Applying a natural barrier balm can help protect the skin from further moisture damage while keeping it nourished. Mud Stuff is a 100% natural, anti-fungal and anti-bacterial balm formulated to soothe and protect the skin on your horse's legs from wet, muddy conditions. Its ingredients â including Nigella sativa (black seed oil), neem, lavender and tea tree â help support the skin's natural barrier and calm irritation. Apply a small amount to clean, dry skin daily during muddy or wet conditions.
For horses that are also showing general skin irritation, itching or rubbing elsewhere, the Original Stinky Stuff (Ultimate Horse Care Pack) provides a complete natural skin care system that can be used as a massage rub, shampoo wash or fly spray for broader skin support.
Supporting skin health from the inside can also make a difference. Non-Stinky Stuff is a 100% natural feed supplement that supports healthy skin, coat and overall wellbeing, helping the skin stay resilient during challenging conditions.
When Should You Involve Your Vet?
While mild mud fever can often be managed with good routine care, you should consult your vet if the scabbing is widespread or deep, there is significant swelling or heat in the leg, your horse is lame or reluctant to move, the condition doesn't improve within a week of consistent care, or there are signs of secondary infection such as discharge or an unpleasant smell.
Severe mud fever can occasionally lead to complications like cellulitis, so it's always better to seek advice sooner rather than later if you're unsure.
Early Detection Makes All the Difference
Mud fever is far easier to manage when it's caught early. By making quick, hands-on leg checks part of your daily routine, you can spot the first signs of redness, roughness or scabbing before they develop into something more uncomfortable for your horse.
Supporting the skin naturally â by keeping legs dry, protecting the skin barrier and nourishing from within â gives your horse the best chance of staying comfortable through the wetter months.
If your horse is prone to mud fever, Mud Stuff offers a simple, 100% natural way to protect and soothe the skin on the legs, heels and lower limbs. Gentle enough for daily use, it's designed to help keep the skin comfortable even during the muddiest conditions.