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.
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:
- Red Clover;
- Fenugreek, and
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