Mud fever is caused by a bacteria, Dermatophilus congolensis. This is ubiquitous as it lives in the soil.
Mud Fever - to Wash or Not to Wash!?
Mud fever is caused by a bacteria, Dermatophilus congolensis. This is ubiquitous as it lives in the soil. It can't invade normal, dry skin, but it can cause problems where skin becomes damaged e.g. cuts, abrasions, or excessively moist, which in some horses causes chapping of the skin allowing the bacteria in. Thus dermatitis caused by D. congolensis can be seen due to sweating under rugs, wetting by the rain (rainscald) or repeated wetting of legs in muddy conditions (mud fever).
D. congolensis infection can be seen in both winter and summer. The lesions tend to be smaller in summer with 1- 2mm lumps in the coat & a moth eaten appearance which can affect large areas. In winter, the hair becomes matted with the discharge & forms large crusts, which when removed, leave a hairless ulcerated skin below. Scabs contain high numbers of the bacteria and so should be disposed of carefully. Grooming kits should also be disinfected after use on and infected horse.
Some horses seem to be resistant to infection, whilst others are particularly prone, probably due to a poor skin immune system & poor circulation to the legs. Feathered legs are usually less often affected as the feathers offer protection from both the wet and the cold. Minimising repeated wetting/drying cycles reduces the likelihood of chapping and thus letting the bacteria in.
Prevention of Mud Fever
Prevent the skin from chapping - DON'T hose down muddy legs but allow the mud to dry and then brush it off. Breathable bandages such as the Premier Equine Quick Dry wraps can speed up drying. If this is not an option, then it is very important that the legs are dried thoroughly after washing & ideally washed with warm water to minimise chapping.
Application of a barrier cream to DRY and CLEAN legs prior to exercise or turnout will help to prevent the skin coming into contact with the bacteria e.g. Muddy Marvel barrier cream which contains chlorhexidine & triclosan (both potent antibacterial) or Lincoln Mud.
Kure Cream which has been tested by Lincoln University & proven to prevent & treat infections (contains Metalosan-45).
If bandaging prior to exercise, ensure the legs are clean and dry beforehand and removed immediately afterwards to avoid any grit or coarse material traumatising the skin surface.
Ensure that bedding is clean, dry and non-irritant to the lower limbs
Consider the use of nutritional supplements to promote healthy skin – zinc is important.
Inspect your horse’s legs daily to spot any early signs of infection.
Treatment of Mud Fever:
Soak off crusts in affected areas – just pulling off crusts is painful & damages the skin further allowing deeper infection so soaking to soften the scabs is important. Tea towels soaked in warm water/chlorhexidine (Hibiscrub) wrapped around & bandaged in place can work well.
Once crusts are removed thorough gentle clean with chlorhexidine, leaving it on for 10 - 15 minutes to allow it to work before rinsing off.
DRY legs thoroughly with clean towels.
It may be beneficial to clip the hair from the area to allow better access to the skin & more rapid drying.
Apply (to dry legs) Lincoln Muddy Buddy Magic Mud Kure Powder if keeping stabled.
Apply the powder and the Mud Kure Cream if turning out.
If it goes wrong
Hopefully it won’t but if the infection is particularly bad, it can cause a cellulitis (deeper infection) which would require a visit & examination by the vet who could then prescribe antibiotics and anti-inflammatories as appropriate.