Rain Rot and Hot Spots: The Summertime Blues

Spring and summer bring colorful gardens, lush pastures, and long sun-filled days. Unfortunately, for many of us, it also brings plenty of rain and humidity, which means rain rot season. Dermatophilosis – commonly called rain rot or rain scald – is a highly contagious bacterial skin infection in horses and cattle (and even dogs, where the wounds are known as hot spots).

While the bacteria that causes rain rot is commonly found on the skin of most mammals without causing problems, when an animal’s skin and hair coat remain wet for long periods (typically due to rain, but also as a result of sweating under blankets or on hot, humid days), the bacteria become inflamed and mobile. The constant dampness also weakens the animals’ outer layer of skin. This creates a ready intrusion point for the bacteria to enter through tiny wounds or insect bites.

Horses or cattle with compromised immune systems, systemic disease, poor nutrition, or allergies are more likely to be affected by rain rot, but it can affect healthy animals as well and is easily spread between animals via insects and grooming tools.

Signs of Rain Rot

Early signs of infection include dry, flaky skin, a dull coat, and small, raised bumps or pustules that can be felt on the skin. As the infection worsens, the pustules grow into crusty scabs that may have yellow pus around the edges. Animals will lose patches of hair above the scabs.

Most often, the affected areas generally include the top of the head, back, and flanks/hindquarters, but rain rot can also occur on the neck or chest. In addition, animals that stand in deep mud can get rain rot on their lower legs. The infection is uncomfortable and can be painful to the point that the animal will flinch when the scabs are touched.


Removal of dead hair and scabs is necessary to halt the progress of the infection. Scabs and hair should be thrown into the trash as they carry live bacteria. If weather is not conducive to shampooing the animal, antiseptic sprays or creams can be worked into the hair to soften the scabs before removal. Otherwise, daily shampooing and scab removal for 3-5 days should halt the progress of the infection. All grooming tools should be thoroughly cleaned after each use and not used on any other animal.

Be sure to consult with your veterinarian on the best course of action for your horse or other livestock, as some cases will require a systemic antibiotic and/or prescription shampoo for a full recovery.

Curicyn’s Hot Spot Formula can help relieve the irritation and inflammation resulting from rain rot and hot spots, as well as a variety of other skin disorders. The soothing formulation does not sting when applied and promotes a more rapid healing environment. Additionally, our Dual Action Gel protects wounds and repels insect activity during the healing process by forming a “second skin” over the wound and helping to eliminate bacteria. Both products are non-toxic, steroid-, and antibiotic-free.

Catching rain rot early offers the best chance to stop the infection quickly. Keep an eye on your horses and other livestock for signs of rain rot infection, especially during wet and humid days.