Rain Rot in Horses

Br: Dr. Lydia Gray | Updated December 5, 2023
rain rot on horses coat

What is Rain Rot in Horses?

Rain rot is a skin infection caused by the bacteria Dermatophilus congolensis. Although the bacteria is present in the environment all the time, it requires a moist environment and a break in the skin to develop into the characteristic hard, painful crusts over a horse’s back and rump.

These crusts are distinctive not only because of where they occur on the horse’s body, but also because when removed, hairs stick through the scab and look like a mini "paintbrush." Rain rot is an unsightly condition that may also prevent a horse from being worked until the skin heals.

Treatment for Rain Rot in Horses

Chestnut horse's cheek covered in mud
A muddy environment could put a horse's skin at risk for developing rain rot.

The best treatment for rain rot is removal of the scabs so that dry air and sunlight can reach the skin. Since the crusts are hard and painful, it may be necessary to soak and soften them first with an antibacterial bath. Horses that are severely affected or ill may also need injections of the antibiotic penicillin.

Preventing Rain Rot and Other Skin Conditions

Although some horses are susceptible to Dermatophilus no matter how well they are cared for, certain steps can be taken to try and avoid the infection.

Ask the Vet Video on Rain Rot in Horses

SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.