Rainscald (also known as dermatophilosis, rain rot and streptothricosis) is a common skin disease in horses that is caused by the bacterium Dermatophilus congolensis. This is the same organism that causes Mud fever in horses. This disease is very common in cows, sheep and goats and is also found occasionally in cats, dogs, and humans. D. congolensis is a gram-positive bacterium that is thought to originate from the soil. It commonly causes disease in moist tropical areas, but can also be found in wet northern environments. Moisture and high temperatures facilitate the dispersal and penetration of zoospores into the skin, contributing to the spread of the disease. Ticks, biting flies, and contact with other infected animals also causes the spread of rainscald. Once in the skin, the bacteria cause inflammation of the skin as well as the typical symptoms associated with rainscald.