Moisture is a classic trigger for mud fever, which is why the problem occurs particularly frequently in the wet months from fall to spring. If the horse stands a lot in mud or damp bedding, the skin in the fetlock bends swells. If it is not dried sufficiently afterwards, it can crack. This results in tiny injuries that are ideal entry points for bacteria.

The penetration of germs initially leads to superficial inflammation, which can spread to deeper layers of the skin if left untreated. This damages the hair follicles and the surrounding connective tissue, which leads to crusts, pain and sometimes purulent secretions. If the inflammation persists, the tissue reacts with thickening and increased horn formation – a typical picture of chronic mauke

How husbandry and care influence the risk

• Wet bedding and muddy pastures/paddocks: wet or ammonia-containing soils irritate the skin and promote cracks.


• Gaiters and bandages: they can trap heat and moisture – ideal for germs if they are not cleaned and dried regularly.


• Clipping and brushing: clipping too short or hard brushing can cause mechanical damage to the skin surface.


• Washing: Frequent washing with highly degreasing shampoos can disrupt the natural lipid layer, dry out the skin and make it more vulnerable.
  
  The rule of thumb: clean, but not over-processed.

Why does mauke occur so often on white legs?

Many horse owners notice that mauke occurs particularly often on white legs. A Swiss study conducted by the University of Zurich on 50 young warmbloods confirmed this impression: horses with light-colored, unpigmented skin in the fetlock bends developed skin irritations and mastitis significantly more frequently. Light-colored skin reacts more sensitively to moisture and UV radiation. The natural barrier is more easily damaged, making it easier for germs to penetrate.

Cold-blooded horses are also more frequently affected by mauke than some other breeds. However, the breed itself only plays an indirect role. Cold-blooded horses have thick coats, which means that moisture and dirt stick to the fetlock bends for longer. This favors mauke.

Why a disturbed skin flora favors Mauke

The horse’s skin is not a sterile system; countless microorganisms live on its surface and are in a delicate balance. If this microbiome gets out of balance, for example due to prolonged wetness, frequent washing or overly harsh ointments, the beneficial germs lose their protective function. Pathogenic bacteria then have an easy time of it.

A Swiss study (Kaiser-Thom et al. 2021) showed that the bacterial diversity on diseased fetlock flexures was significantly lower than on healthy skin areas. A further study ( Sangiorgio et al. 2021) also found that the more severe the skin changes and the more frequently antimicrobial agents were used, the more biased the microbial composition became.

This supports the assumption of many vets that excessive or overly “sterile” care can do more harm than good to the skin flora – because it displaces the very microorganisms that actually protect against mumps.

Is Mauke contagious?

Mauke is not normally directly contagious. However, a mite infestation can affect several horses in the same herd and trigger or exacerbate mastitis – especially in the cold and damp season.

However, infectious pathogens are exceptions: in 2021 to 2022, there was a major outbreak of skin infections on the fetlocks of many horses in Finland. Researchers found a new virus from the smallpox family that was probably the cause ( Virtanen et al. 2023). This virus is similar to pathogens that can cause skin lesions in humans. In individual cases, skin irritation occurred in people in contact with sick horses, but an actual infection could not be confirmed.

In another Finnish study, certain bacteria belonging to the same group as the pathogens that cause diphtheria (Grönthal et al. 2024). In principle, these germs can also cause disease in humans, but there have been no proven transmissions in this context.

So: Mauke is generally not contagious. In rare outbreaks or co-infection cases, an infectious component may play a role and veterinary clarification is then advisable.

From equipment to supplementary feed: Preventing moulting

1. Floor care: Drain, avoid muddy areas, create dry retreat areas


2. Change bedding regularly and remove wet spots immediately


3. Dry legs carefully with a clean towel after rain or washing


4. Keep equipment (gaiters, bandages, blankets, grooming kit) clean


5. Check feeding: A lack of zinc or biotin can weaken the skin barrier (this is considered a potential factor, not the sole cause)

Early detection remains essential: small rednesses or moist skin should be observed immediately before crusts form.