Rainrot is one of the most common bacterial skin infections seen in horses and is often mistaken as a fungal disease.  It is also referred to as dermatophilus congolensis (derm-ah-TOF-ill-us  con-go-LEN-sis).  It is characterized by crust-like scabs or small ¼ inch matted tufts of hair.  The organism that causes rain rot appears and multiplies in warm, damp conditions often with high temperatures and high humidity present.  The condition is not life-threating, so don’t worry.  However, while the horse has rain rot, any equipment that may rub and irritate the infected skin (brushes, saddles, leg wraps, etc.) should not be used on another horse and should eventually be washed with an anti-microbial solution to eliminate spreading of the disease or a reinfection.

What causes rain rot?

The dermatophilus congolensis organism causes rain rot. Most people believe that the organism is present in the soil, however, this has not been proven. During dry weather, the bacteria remains dormant on a horse, but can spread from horse to horse by direct contact, contaminated tack and grooming equipment or external parasites. Some horses can be chronically affected with the bacteria, but do not show any symptoms or develop the skin disease. These horses are called carriers. The skin has to be damaged (cut, scraped, bug bite, etc.) or compromised due to prolonged high humidity, rain, etc. for the horse to get afflicted. Anything that compromises a horse’s immunity—advanced age, malnutrition, illness—can make him more susceptible to the infection, as can having a heavy winter coat, which tends to trap moisture against the skin.

What does rain rot look like?

Rain rot can appear as large crust-like scabs or small ¼ inch matted tufts of hair. In the early stages, you will be able to feel small lumps on the horse’s skin or hair by running your hand over your horse’s coat. Be sure to wash your hands with anti-microbial soap after touching this area in order to avoid spreading.

The crusts form on parts of the body that are chronically damp—often along the topline and where rain runs off down the barrel, shoulders or hindquarters, but also on the lower legs or faces of horses who regularly stand in mud or graze tall, wet grass. Over time, the crusts peel off, leaving small, round bare spots; pus may also be seen under newly sloughed scabs.

Where does rain rot normally occur?

Rain rot is usually seen over the back, hindquarters, back of pasterns or on the hind cannons. The disease can be worse over white skinned areas. Because the skin needs to be damaged or compromised for the disease to spread, it often occurs where the saddle, stirrups, halter and cinch touches your horse.

Will rain rot go away on its own?

It sometimes does however treatment is recommended even in minor cases because the lesions can spread and worsen. The lesions can interfere with use, especially if they are located along the horse’s back or withers, and they may be painful for the horse when rubbed or pulled. The affected area can also be susceptible to secondary skin infections.

How does rain rot spread?

Rain rot can spread through sharing of equipment with an infected horse. This includes saddle pads, blankets, leg wraps, brushes, halters, etc. It can also be passed from one horse to another if they come in close contact.

Is rain rot painful for my horse?

No, the lesions do not hurt the horse and have not been associated with an itchy feeling either. However, it may be painful and uncomfortable to remove the scabs and if rubbed by a blanket, saddle, halter, etc. may cause discomfort. We do not recommend removing the scabs. Resolve will be effective without any discomfort to your horse and therefore safer to apply.

What treatment should I use to resolve rain rot and prevent it from reoccurring?

Our horses are often out in the pasture and cannot be brought in or remain in a dry stall, therefore we recommend the following steps to resolve rain rot and prevent it from reoccurring:

  1. For rain rot and other conditions known as scratches, mud-rash, rain scald and saddle rash, thrush, ring worm and other skin irritations such as insect bites and itchy tails – There is no need to shampoo your horse before applying Resolve.  Saturate only the affect area once a day.  Continue applying once a day until healing is evident.   Then apply twice weekly until problem is completely eliminated.  It is not necessary to remove scabs or clip hair to be effective.     If you are able to remove the scabs safely (this can be painful or uncomfortable to your horse) be sure to discard the scabs and wash your hands with an anti-microbial solution or use gloves in order to prevent further contamination to other horses or yourself.  The scabs can remain contagious for many months.
  2. To help prevent rain rot from returning, periodically apply Resolve in the area it often occurs when there is high humidity and frequent rain.
  3. For ring worm – Apply to affected area every 3 days for 4 – 6 treatments.  If condition persists, consult with your veterinarian.
  4. For thrush – Clean hoof area of dirt (preferred method is to trim back the frog) and debris so Resolve can reach the affected tissue.  Apply once a day until healing is evident. Apply periodically as a preventative measure.  If condition persists, consult with your veterinarian.
  5. Do not share equipment ie. blankets, halters, brushes, combs, etc. with other horses.  If possible disinfect your equipment with an anti-microbial solution, wear gloves and always wash your hand with an anti-microbial soap to reduce contamination.

Rainrot Phase 1


Rainrot Phase 2


Rainrot Phase 3