In the UK we’ve been very fortunate to have an unusually dry autumn and early winter, making horse management much easier. The rain has now arrived, and with it comes that pesky yet inevitable sea of mud. For some horse owners this means the arrival of mud fever, or Dermatophilus congolensis to give it its medical name.
Prolonged wetting of the skin and a covering of mud that can stop air getting to the skin can allow an infection of the mud fever organism to take hold. It is classed as an actinomycete, which means it behaves like both a bacteria and a fungi. The organism exists on the skin, but it’s when the skin’s barrier function is impaired that infection can take hold. Secondly bacterial infections can occur once the skin is damaged by mud fever.
Mud fever is much easier prevented that cured, so be sure to keep an eye out for the early signs which include clumping of hair and reddening of the skin on the lower extremities, followed by the development of scabs.
Poached fields increase the risk of mud fever.
Following are some tips about how to avoid and manage mud fever from the inside and on the outside.
From the inside, the most important factor is a balanced diet, with adequate supplementation of the essential vitamins and minerals that are short in forage, especially for horses who don’t need much fortified compound feed (nuts and coarse mixes). Zinc and copper are both key nutrients for healthy skin, and vitamins A and E are key for a healthy immune system – and all four nutrients are always short in preserved forages e.g. hay and haylage. Extra skin support can be given via omega-3 fatty acids e.g. from linseed (flaxseed) oil and from herbal supplements.
From the outside, the key factors are to stop the skin getting softened from prolonged contact with mud and water, and to regularly wash off mud. Washing off mud (with care – do not scrub because you risk damaging the skin) allows the skin to be checked and also allows air circulation. Applying barrier creams and/or oils after drying can help repel the moisture and mud. The skin should not be washed every day because doing so can dry it out and remove beneficial bacteria, both of which will help mud fever take hold. However, washing the mud off a couple of times per week from horses who live out and applying barrier lotions or creams does seem to help prevent the condition.
Feathers may help reduce the risk of mud fever if they are thick enough to stop moisture getting into the skin, but on the other hand – and especially with deep mud – they may also increase the risk by holding moisture in. Clipping of feathers is recommended if the latter is the case, and/or if mud fever has taken hold, so that the skin can be treated effectively.
If infection has taken hold, use an antifungal and antibacterial in the first wash or two, but then stop using such agents to allow any scabs or open skin to heal well. Don’t hesitate to call the vet if the condition does not improve or the area becomes swollen. With more severe cases, many vets are having good success with using silver sulphadiazine creams and dressings.