Warding Off Rain Rot

I don’t know about you, but we’ve had a ton of rain in my neck of the woods lately. Like flooding conditions on several occasions (so much for using our new boat any time soon. . .), but despite the rain levels, one thing I’ve never dealt with is a condition in horses called rain rot.

Technically known as dermatophilosis, this condition is often mistakenly believed to be caused by a fungus but is actually caused by a bacterial infection. The bacterium, Dermatophilus congolensis, is to blame.

According to Merck Veterinary Manual, this bacterium lives dormant within the skin until the skin becomes compromised in some way. This can happen when there’s prolonged wetness, high humidity, high temperatures, or even attacks by biting insects.

Interestingly enough, Dermatophilus congolensis is also responsible for heel dermatitis, or scratches (also known as Mud Fever). 

Rain rot is most often seen in horses with compromised immune systems (from improper nutrition, old age, or Cushing’s disease), but it is possible for biting insects to spread the infection from horse to horse. Shared saddle pads or grooming supplies can also spread the bacteria.

rain rot


Fortunately, rain rot is fairly easy to identify because of the peeling skin lesions which scab over, often leaving bald spots once they come off. But a veterinarian can confirm the diagnosis by examining a skin scraping under the microscope and/or having it cultured.


Treating Rain Rot

Rain rot can actually clear up on its own (if weather conditions improve), but you may want to hasten your horse’s recovery by using an iodine-based, medicated, or herbal shampoo and/or topical treatment. In the early stages, a tea tree-based shampoo may help, but according to Horse Journal, Absorbine Medicated Twin Pack Shampoo and Spray is a better option for moderate cases. Horse Journal also recommends the tea tree oil-based sheath cleaner, Excalibur by Farnam for using on areas with thick scabbing. Vetricyn spray is another topical option.

Additionally, acupressure or acupuncture can be used to help stimulate the immune system. See video below for specific acu-points.


Some essential oils (aside from tea tree oil) which may help include:

(***Remember to always dilute your EO’s in a carrier such as aloe vera gel.)

Helpful herbs to feed include:

  • Chickweed;
  • Nettle;
  • Red Clover;
  • Licorice;
  • Echinacea;
  • Fenugreek, and
  • Dandelion.


Preventing Rain Rot

Since rain rot is associated with a compromised immune system, supporting your horse with nutrition is one of the best ways to prevent the condition. Trace minerals, especially copper and sulfur should not be neglected. (Feeding MSM is one way to add supplementary sulfur.)

Since biting flies can also aid in the initial infection as well as spread of rain rot, using fly sheets and mesh leg covering may be helpful (especially in older horses, whose immune systems are often compromised due to age). Manure management in the pasture can also help to cut down on flies.

If your horse is prone to rain rot, or if you just want to take extra precautions, dried nettle leaves or dandelion may be helpful (can feed the leaves or make a tea).

Additionally, if any of your horses do experience rain rot, it’s important to disinfect grooming supplies and not share tack between horses–otherwise you’re risking spreading the infection.



Sources and Further Reading 

Understanding Rain Rot

Rain Rot Treatments for Horses

Relieve Rain Rot




Hi! My name is Casie Bazay. I'm a mom, a freelance writer, and a certified equine acupressure practitioner.

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3 Responses

  1. Rebekah says:

    Rain Rot, now there is something my Gelding had when I first got him from his previous owner and to think about it, I have had him for almost 2 years now and have not see rain rot in him since! I’m amazed. Now one year we had constant rain for 4 weeks straight and my main concern although he had rain rot when I first got him was actually abscess in his hoof.

    I have a 17H Gelding Pain horse that has several issues. First is joints, he has flat feet, and prone to abscess during rainy season, not to mention the bitting flies on top of all that. I thought his coat looked good until just 2 weeks ago with all his coat already shedded, I looked at him and saw how shiny he was.

    First of all, I completely change his diet in 2015 to an all natural diet consist of Timothy pellets from Standlee cause they use allot less pesticides on their grass than the other competitors. I incorporate Alfafa cubes, Rice bran, oats, Copra Coolstance, Bee Pollen and last but not least, granules garlic. During the summer months once he’s on pasture, he gets Timothy pellets, a few alfalfa cubes, Coolstance, rice bran and garlic. During the winter months, I incorporate the Oats and I increase the dose, as the summer dose its only to hide the taste of the garlic.

    Second, I removed him (2015 August) from the supplement that he was on for his joints, the chemically enhance, the famous “Cosequin” that only worked on his joints, and I immediately put him a all natural organic product from springtimeinc.com for Joint health… and OH MY GOD, I have an improved all around horse.

    The supplement I used for his joints has helped his abscess problem, because after him being on that for 7 months and after we got that down poor of rain the following year April I was sure I would not be able to ride him for a month, at the very least. Nop, not a sign of abscess in sight. So not only is he doing good with his joints, but his abscess problem no longer exists.

    I believe he doesn’t have rain rot from the time I got him until now because of what I feed him. The fact that he is in a all natural diet, and when winter comes, I turn to a source that does not use pesticides on their grass for the hay, so that also is all natural grown.

    Now, as for as his coat and why he is so shiny after almost 2 years. I believe it’s the Coconut Copra Coolstance that I have been feeding him from day one during winter times. Yes, it helps to improve weight as I have experience a problem with my other horse, a mare that is a hard keeper. Now because she is not on the same joint supplements as my gelding, I have to say that the Coolstance is the reason why their coats are so shiny and oh my God so smooth to the touch, it feels like silk. I can longer brush their coats with a regular brush, I have to use the ever so soft brush for face in order to brush them and remove the dust from them unless it’s stuck on mud than I’ll use the tough brush as I had in the past for their coats. My mare who has an overall healthy body at only 5 years of age to shed her coat within a month, it took my Gelding 3 months to shed his coat, and I had to help him because the itch was awful.

    Garlic, well, it speaks for it self…As it deters horse bitting flies, mosquitoes, black flies, ticks, nats and the regular house flies that you see on horse faces all the time, not my horses because they are on garlic. Garlic was the first supplements that I give to my Mare when I first got her and within 4 weeks and progressing, she had zero flies on her face.

    So my words are, if you really love your horse and you have the money, I say change their diets to a more all natural diet with no added chemicals, no pesticides, and add garlic because you will be amazed. You have a horse with joint problems and or abscess, joint health supplements from springtimeinc.com will completely fix that problem. Like I said, I had nothing to loose and everything to gain.

    Both my horses are so very healthy, well at least my Mare is, she was only 1.5 years old when I got her, but my Gelding who was already up there in age 11 years old when I got him, I am seeing a huge improvement on his overall health of the all natural diet. But he still have another few years before he is completely healthy, as it takes time to heel what was once destroyed with chemical processed feeds.

  2. Candice says:

    Muck-Itch is a fantastic product for treating rain rot. It was developed in South Florida…land of rain rot. It has essential oils and never irritates the skin.

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