Rain Rot in Horses

Rain rot is also known as rain scald. It's a kind of skin disease in horses that's caused by bacteria. Rain rot can sometimes be mistaken for a fungal infection of the skin. Horses will have this kind of disease if their body is always wet or moist, due to continuous rain or humid atmospheric conditions.


Dermatophilus congolensis is the name of the bacteria that causes rain rot in horses. The bacteria are found in the skin of horses, but they're just in a dormant state. They will only infect the horse's skin if it's always wet or moist, the temperature and humidity are high, and lots of insects bite. In instances when the humidity is high, the population of biting insects will increase and this will lead to the spread of the skin infection to other horses on the ranch.

The horses will suffer from skin lesions and inflamed infected area. The affected area is not itchy at all, but it is painful for the horse when touched. The body areas of the horses that are commonly infected are back, neck, croup, withers, and lower limbs. The skin area where the color is lighter is usually the most affected. When one lesion connects to a nearby lesion, the infection grows. A scab or crust is formed, and when the crust is removed, some yellow-green colored pus is evident.

Prevention and Treatment

Horse owners must always practice good hygiene to prevent rain rot in horses. Always use clean and disinfected brushes and do daily grooming. If possible, each horse should have its own set of grooming tools to prevent the spread of infection. Keep the ranch clean, dry, and well-insulated to control the population of biting insects, and keep humidity at a desirable level. Don't leave your horses out in the rain for long periods of time. Keep them inside the barn where they'll be dry and safe.

In situations where one of the horses is already infected with rain rot, it's best to immediately put the horse in quarantine to avoid the spread of the disease to other horses. All its grooming tools should always be disinfected before each use.

When the infection is only mild, there's a possibility that it can heal on its own without any medication. However, it's still recommended to put the horse under medication even if the infection is very small. There's still a high risk that it will spread to the other areas of the skin and the condition will get worse, especially if good hygiene and quarantine are not observed.

Peeling off the scabs and using shampoos with antimicrobial properties during bath and currying will treat mild infection of rain rot. Please be careful and gentle when peeling off the scabs, because it will be painful for the horses if done carelessly.

However, when the horses are already suffering from severe rain rot infection, it's best to consult a veterinarian for medication. The infection is not only affecting a single layer of skin, but multiple layers of skin. The veterinarian will prescribe antibiotics to combat the infection and heal the horses in time.

Rain rot may not be fatal to horses. However, because of the pain that they feel when the affected skin is touched, it will be like torture for the horse to do its daily tasks, especially if the affected areas always rub against the saddle. It's a good habit for horse owners to provide proper treatment for their horses, even if the infection is still in small degree, to give comfort and rest to their loyal allies.