Also Known As

Rain scald, mud fever


Dermatophilosis is a skin infection caused by the bacteria Dematophilus congolensis. The bacteria thrives in muddy, wet conditions, and enters through damaged skin or sores. In some cases, it may be mistaken for ringworm. The infestations of bacteria create pus that sticks to the ends of tufts of hair. When the tufts of hair fall out, scabs form over collections of pus in the tissues.

When the disease is on the legs, it is often referred to as mud fever. When the bacterial infestations are on the body, it is known as rain scald. If not treated promptly, secondary infections by Streptococci and Staphylococci may occur.


  • Pus-filled sores and scabs
  • Tufts of matted hair with pus on the tips
  • Tender, painful areas


The cause of rain scald is the bacteria Dermatophilus congolensis which becomes active in wet, soggy pastures, and during the rainy season of the year. .


Keeping horses in dry areas with dry bedding and stalls is the best prevention.


Horses should be stabled in dry conditions. The infection is responsive to a course of antibiotics, and topical agents work well. Infected areas should be clipped out, and scabs softened and lifted off. If scabs are not easily removed, soak or shampoo until they soften and can be gently removed with a soft brush.

If possible, burn the tufts of hair and scabs to prevent further infection of other animals. A veterinarian-recommended antibacterial wash in warm water should be used to cleanse the areas, after which they should be patted dry with absorbent paper towels. Continue the treatments until the skin heals.

If staph infection is suspected, have the veterinarian do a culture since further treatment may be necessary.

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