Greasy heel (tail mange/dermatitis) in horses

What is mud fever?

Mud fever (pastern dermatitis) is not a single disease but a skin reaction pattern in the pastern and pastern hollow area. The underlying cause differs per horse and may consist of bacteria (Dermatophilus congolensis, Staphylococcus spp.), fungi, mites (Chorioptes bovis) or an immune-mediated vasculitis [1][2]. Damp and muddy conditions are the main precipitating factor.

Non-pigmented (white) legs are significantly more often and more severely affected than pigmented legs [2]. This difference is not coincidental: melanin provides an extra barrier function to the skin.

Standard basic treatment

Regardless of the cause, the same hygienic basis applies:

• Wash the affected skin with a chlorhexidine- or iodine-containing shampoo.
• Remove scabs carefully after soaking; do not force.
• Ensure a dry, clean environment — this is the most effective measure.
• Antibiotics only on indication, preferably based on culture and antibiogram.

In treatment-resistant mud fever, a biopsy is the only reliable way to establish the actual cause [1]. Empirically administering antibiotics without a diagnosis increases the risk of resistance and does not resolve the underlying cause.

What does the evidence say about additional options?

Essential fatty acids and phytosphingosine

An epidemiological study evaluated a spot-on with essential fatty acids and phytosphingosine as a preventive measure in young horses [2]. The results are descriptive; without placebo control, the effect cannot be distinguished from spontaneous recovery. Evidence: insufficient to justify a recommendation.

Topical ivermectin in Chorioptes mange

In mud fever caused by Chorioptes bovis — difficult to recognise without microscopic skin examination — topical ivermectin shows promising results in two published case reports in Belgian draught horse foals [3]. Systemic moxidectine is not always sufficiently effective. As these are case reports, generalisation is limited. Use this product exclusively on veterinary advice.

Immune-mediated pastern vasculitis

Leucocytoclastic vasculitis is a specific variant with a poor prognosis and requires corticosteroids, sometimes in combination with pentoxifylline as a synergistic agent [1]. No natural product has been studied in this variant. Self-treatment is not appropriate here.

Additional ≠ replacement

Supportive measures such as a dry stable, protection of white legs against mud and good nutrition have a logical basis but have not been tested in controlled trials. They can support veterinary treatment but not replace it. The cause of mud fever determines the treatment — and that cause cannot be known without examination.