Rain Scald and Mud Fever
These are essentially the same conditions on different parts of the horse. Both are caused by the same bacterium, Dermatophilus congolensis, which thrives on wet skin. On a horse’s back, this infection is Rain Scald, on its legs it is Mud Fever. Often with Mud Fever, other opportunistic bacteria join in and create nasty mixed infections.
The bacteria will die in dry conditions so the golden rule of treating mud fever is to get the legs absolutely dry which means clipping the hair and removing any scabs
Treating Mild Mud Fever
(Small patches, not that sore to touch, no swelling or lameness)
Remove any scabs – this is crucial. Underneath scabs there is plenty of moisture and the bacteria is quite happy. The scabs will also protect the bacteria from any creams or washes applied topically. Apply Dermisol® cream overnight and then gently pick off the scabs.
Clip the hair coat as close as possible to the skin – hair holds moisture and sweat and creates a damp micro-environment next to the skin allowing the bacteria to survive even if the outer coat looks dry
Wash the area with dilute Hibiscrub® – do not overdo the Hibiscrub; once every other day is plenty
Dry the leg thoroughly with a clean towel
Use talc (try Cuticura Talc®) to really dry the skin
Keep the horse in. If the legs are swelling up from the box rest, do some gentle lunging or riding rather than turning the horse out. Just make sure you dry the legs off thoroughly when you are finished
Treating Severe Mud Fever
(Lots of scabbing, painful to touch, leg swollen, horse lame)
Remove any scabs. Removing scabs on a horse with sore legs can be difficult. Apply a thick layer of Dermisol® cream, wrap clingfilm around the leg and cover with a stable bandage (it is crucial that the horse is unable to get at the clingfilm and eat it). Leave this overnight and then in the morning the scabs can be easily removed. Do not repeat this procedure unless instructed by us; it does moisten the skin and can be counter-productive if done too many times.
We can then come out the next day, sedate the horse and clip the legs. Once properly softened the scabs come off easily with the clippers but be warned, there can be a fair bit of bleeding.
Wash the area with dilute Hibiscrub®. Do not overuse Hibiscrub®; for day to day cleaning water is fine since you will be using an antibiotic cream anyway.
Dry the leg thoroughly with a clean towel.
Apply antibiotic cream once daily to the affected areas. Topical cloxacillin cream often works the best.
If we are concerned we may put the horse on a course of oral antibiotics as well. Oral antibiotics often do not help much with the Mud Fever but they can stop nasty leg infections developing.
If the treatment is not working we may need to take swabs to confirm which bacteria are involved and which antibiotics they are sensitive to.
Keep the horse in until you are absolutely certain that the Mud Fever is completely cured. Letting the horse out again into wet, muddy conditions too soon will set everything off again which can be very dispiriting.
Preventing Mud Fever
This is a much debated subject. There are many barrier creams available and many seem to work well. Bear in mind that if the barrier cream is greasy then it will trap sweat underneath it which will lead to moist skin. When you bring the horse in, make sure you remove all traces of the barrier cream and dry the legs thoroughly.
Not surprisingly, we recommend keeping the hair clipped reasonably short especially on heavily feathered breeds.
Keep the horse in during very wet periods.
If you are buying a horse, bear in mind that white legs are worse affected than dark legs.
If all else fails, emigrate!