02/04/2026
๐๐ซ๐๐๐ฌ๐ฒ ๐๐๐๐ฅ ๐ข๐ง ๐๐จ๐ซ๐ฌ๐๐ฌ: ๐๐ง๐๐๐ซ๐ฌ๐ญ๐๐ง๐๐ข๐ง๐ , ๐๐ซ๐๐๐ญ๐ข๐ง๐ , ๐๐ง๐ ๐๐ซ๐๐ฏ๐๐ง๐ญ๐ข๐ง๐ ๐๐๐ฌ๐ญ๐๐ซ๐ง ๐๐๐ซ๐ฆ๐๐ญ๐ข๐ญ๐ข๐ฌ
Greasy heelโalso commonly known as mud feverโis one of the most frustrating skin conditions horse owners face. More correctly termed pastern dermatitis, this condition is not a single disease but a complex syndrome with multiple contributing factors, making it tricky to treat and even harder to prevent long-term.
1. What is Pastern Dermatitis?
Pastern dermatitis is a non-specific inflammatory skin condition affecting the lower limb, typically around the pastern and heel area.
Rather than being one single disease, it is best described as a reaction pattern of the skinโmeaning different underlying causes can produce very similar symptoms.
Clinical signs can vary in severity and may include:
Redness
Scabs and crusting
Hair loss
Thickened or cracked skin
Oozing lesions in more severe cases
Pain and even lameness
Some cases remain mild and cosmetic, while others become chronic, painful, and performance-limiting.
2. What Causes Pastern Dermatitis?
One of the biggest misconceptions is that greasy heel is simply caused by mud. In reality, it is a multifactorial condition, meaning several contributing factors often combine.
Common contributing factors include:
Moisture and environment
Wet, muddy conditions weaken the skin barrier, making it easier for damage and infection to occur.
Bacterial imbalance
Disruption of the normal skin microbiome allows opportunistic bacteria to take hold.
Parasites (mites)
Particularly in feathered breeds, mites can be a significant trigger.
Skin irritation or damage
Small cuts, chemical irritation from sprays or shampoos, or even sunburn can initiate lesions.
Genetics and pigmentation
White legs and unpigmented skin are more vulnerable.
Immune function
Some horses are simply more predisposed due to underlying immune or inflammatory challenges.
3. Photosensitivity & Diet: The Missing Piece in Many Cases
This is where many greasy heel cases are misunderstood.
Not all pastern dermatitis is caused by mud, bacteria, or mites. In some horsesโparticularly those with white legsโphotosensitivity can be a key underlying driver, and diet can play a major role.
What is Photosensitivity?
Photosensitivity is an abnormal reaction of the skin to sunlight (UV radiation). It causes inflammation and skin damage that can look almost identical to greasy heel.
Signs may include:
Red, inflamed skin
Scabbing and crusting
Oozing or weeping lesions
Cracked, painful skin
Which is why it is so often misdiagnosed.
How Pasture and Plants Contribute
Certain grasses and weedsโparticularly those high in oxalates or other plant compoundsโcan contribute to this issue.
Common examples in Australia include:
Cape W**d
Buffalo Grass
Setaria
Kikuyu
Pigweed and other broadleaf weeds
While oxalates are best known for binding calcium, high-oxalate diets can contribute to metabolic stress and mineral imbalances, which may make horses more susceptible to inflammatory skin conditions.
Two Types of Diet-Related Photosensitivity
1. Primary Photosensitivity
Some plants contain photodynamic compounds that circulate in the bloodstream. When exposed to sunlight, these compounds react and damage skin cells.
2. Secondary Photosensitivity (Liver-Related)
More serious and often overlooked.
Certain plants can impair liver function. When this happens, the horse cannot properly process phylloerythrin, a natural by-product of chlorophyll breakdown.
This compound builds up in the bloodstream and reacts with sunlight, leading to:
Severe skin inflammation
Lesions on white legs and exposed areas
Persistent or worsening โgreasy heelโ symptoms
Why This Matters
If a horse has:
Recurrent greasy heel
Poor response to treatments
Lesions mainly on white legs
Seasonal flare-ups
๐ You may not be dealing with a simple skin infectionโyou may be looking at a diet and metabolic issue presenting through the skin.
4. The Role of Nutrition in Healing and Prevention
This is where long-term success is won or lost.
Topical treatments can help manage symptoms, but nutrition is what supports true healing and resilience.
Key nutritional factors:
Essential fatty acids (EFAs)
Support skin barrier function and help reduce inflammation.
Trace minerals (Zinc & Copper)
Critical for skin repair, immune function, and integrity.
Protein and amino acids
Necessary for tissue repair and regeneration.
Antioxidants
Help reduce oxidative stress and inflammation.
Gut health
The gutโskin connection plays a major role in inflammatory conditions.
Toxin Binders
Bind to certain moulds and other toxins which can cause photosensitivity and also temperament changes.
When photosensitivity is involved:
Nutrition becomes even more important to:
Support liver function
Correct mineral imbalances (especially with high-oxalate intake)
Reduce systemic inflammation
Strengthen the skinโs resistance to UV damage
5. Conditions That Look Like Pastern Dermatitis (But Arenโt)
Accurate diagnosis is essential, as several conditions can appear very similar:
Mite infestations (Chorioptes)
Ringworm (fungal infection)
Photosensitisation
Bacterial cellulitis
๐ Persistent or severe cases should always involve veterinary guidance.
6. How Elite Equine Nutritionโs COMPETE Supports Healing and Prevention
When managing greasy heel, the goal isnโt just to clear itโitโs to build a more resilient horse from the inside out.
Thatโs where COMPETE comes in.
COMPETE supports:
โ Skin repair and integrity
Providing nutrients essential for healing and barrier strength
โ Immune function
Helping the horse respond more effectively to environmental and bacterial challenges
โ Reduced inflammation
A key driver in chronic and recurring cases
โ Metabolic and nutritional balance
Particularly important where diet (such as high-oxalate pasture) is a contributing factor
โ Liver and systemic support
Crucial in cases involving photosensitivity
Why this approach works
If youโve dealt with greasy heel before, youโll know:
It often comes back
It can linger for weeks or months
It doesnโt always respond to creams or washes
Thatโs because youโre often treating the symptom, not the cause.
By combining:
Good environmental management
Correct diagnosis
Appropriate topical care
Targeted nutritional support with COMPETE
โฆyou give the horse the best chance at:
โ Faster healing
โ Reduced recurrence
โ Stronger, healthier skin long-term
We also recommend feeding a good quality Toxin Binder if symptoms persist.
Final Thoughts
Greasy heel isnโt just a mud problemโitโs a whole-horse problem.
And in many cases, especially those involving photosensitivity, itโs actually a reflection of whatโs happening internally.
The most successful outcomes come from addressing:
Environment
Infection
Skin health
And cruciallyโnutrition and metabolic balance
Because when you fix the horse on the inside, the outside has a much better chance of staying healthy.
