Mud Fever and RingWorm in Horses--Signs and Symptoms

Dermatologic conditions in horses can be difficult to diagnose with names like Dermatophilosis and Dermatophytosis—Say What?  It’s no wonder common names like "scratches," "greasy heel," “mud fever” and "girth itch" have emerged. These terms sound like a diagnosis, but they actually describe the signs and symptoms of the skin condition. It may take a veterinarian to come out and take a skin scrape sample to determine the exact problem. But, understanding some of these skin ailments in your horse may help you now and in the future.

Dermatophilosis is a bacterial infection, commonly known as rain rot or mud fever. This infection causes streaks of hair loss that resembles paint brush strokes, oozing, and crusting. White horses or horses with white leg markings are most commonly affected. This can happen in any climate, but mostly in tropical regions where it’s humid, damp and wet.

Pyoderma (or folliculitis) is commonly known as saddle dermatitis, tail dermatitis or pastern dermatitis. It develops when a horse sweats excessively and this causes a shift in the pH balance that favors bacterial growth. Signs and symptoms usually include hair loss, crusting, scaling on the chest and legs and across the back croup. This condition may be preventable if you rinse down your horse after exercise.

Dermatophytosis ("ringworm") is a fungal infection.  Ringworm is very common and misdiagnosed frequently as an equine skin disease. In most classic situations, ringworm starts with hair loss in a localized area that slowly expands to a larger size. Sometimes this makes it difficult to distinguish this from other diseases, especially bacterial infections and sarcoids. Of course, for accurate diagnoses have a veterinarian come out and do a culture of the lesion. Ring worm generally heals up within a few months without treatment; but it is very uncomfortable for the horse and it’s highly contagious to other horses and humans.

Tack and grooming supplies should not be shared, and equipment and even stall walls should be disinfected to prevent spreading the fungus.

We Recommend for Mud Fever and Rain Rot:

Move your affected horse to a dry stall, wear gloves to remove crusty scabs and trim the hair, if applicable around infected area, wash with an antibacterial shampoo, such as, “Castile Dermatitis Shampoo”, pat dry, and treat with “Equine Derma Relief” twice a day for up to two weeks.