Rain rot… What is rain rot? How do you treat rain rot? Can you prevent your horses and other animals from getting rain rot?
How do you get rid of rain rot? Rain rot is a skin infection that can affect livestock. Learn what it is, how to prevent and treat rain rot.
What is rain rot?
Rain rot, sometimes called rain scald, is an infection that is caused by a bacteria. The bacteria that causes rain rot is Dermatophilus congolensis.
The infection occurs when the spores of the bacteria make their way into the skin. Usually the spores cannot get into the skin and don’t cause infection. Conditions must be right for the spores to take hold.
Rain rot occurs the most when the weather is rainy or humid and warm. The areas that are usually affect with rain rot are the areas that are most exposed to rain: the back, shoulders, head and top of the neck. It is rarely seen on the underside of the body or the legs.
The bacterial spores cannot penetrate healthy skin tissue. Spores can only enter damaged tissues or unprotected tissues.
They will enter through cuts, scrapes and even insect bites from fleas, ticks or mosquitoes. When there is excessive rainfall, the natural oils that help to protect the skin are washed away, creating areas where the spores can take hold.
For more information about Dermatophilus congolensis, check out the Merck Veterinary Manual’s article Overview of Dermatophilosis.
The video below is an interview with a veterinarian done by the Horse Supplement company SmartPak. She’s answering questions about rain rot. The information pertains to not just horses, but other livestock as well.
What does rain rot look like?
Rain rot is very easy to distinguish from other conditions. It can be confused with fungal diseases like ringworm. With careful inspection though it can be accurately diagnosed.
D. congolensis spores will create small pustules on the outer layers of skin. These outer layers of tissue die and clump together with the surrounding hair. These small scabs can resemble paintbrushes and are often called paintbrush lesions.
When you rub the animal’s hair, you will be able to feel the pustules and paintbrush lesions. When the infection first begins, it may look spotty and appear in random places. If the condition worsens, it can lead to larger clumps and bare skin.
Woolen sheep will form large pustules under wool, where it can be hard to detect. The pustules create hard, lumpy masses of wool, hence the name lumpy wool.
Sometimes, the only sign of lumpy wool that is visible in sheep is scabs that form on the ears, where there isn’t thick wool.
What animals can get rain rot?
Cattle, sheep, goats, and horses are most commonly affected by rain rot. Pigs, dogs and cats can get rain rot but it is rare in them.
It’s often referred to as rain rot on horses and rain scald on livestock, despite being caused by the same bacteria. When the disease affects the woolen part of sheep, it’s called lumpy wool.
There have only been a few reported cases of rain rot in people. All of the reported cases have been linked to someone caring for an animal that had rain rot.
Severe rain rot
With proper intervention, rain rot is not a serious condition. It is easy to get rid of and usually only affects the skin of the animal and nothing else.
When rain rot is not controlled, the open wounds can create ideal environments for secondary infections. Staphylococcal folliculitis is a common secondary infection of rain rot, a staph infection that occurs in the hair follicle.
Normally rain rot will create very small scabs. These areas heal and the hair grows back within a couple of weeks. If conditions are not changed and the rain rot is not treated, large areas of hair will fall out and create large bald spots.
Can I prevent rain rot?
There are several things that you can do to prevent your animals from getting rain rot.
In many cases, rain scald or rain rot is ‘cured’ when the animal is kept inside from wet conditions. The skin produces the protective oils that prevent the spores from penetrating the skin and the skin heals itself.
Keeping your animals out of the rain is the ideal first step in preventing rain rot. Even a shed or lean-to can provide a dry area for your animals.
If you have horses, make sure that their turn out blankets are waterproof. A water-resistant blanket can become saturated and creates a warm, moist skin environment that is ideal for harboring bacterial spores.
When you bathe your animals, take a few extra minutes to scrape the water off of them to help the skin dry.
Insect bites can create wounds that open the skin up to spores causing rain rot. Keep insect repellent on hand and spray your animals to prevent the tiny wounds that can lead to rain rot.
Sheep are harder to treat due to the thick wool covering affected areas. It’s a good idea to treat your sheep as a precaution after you shear them.
How to get rid of rain rot
If you find that you’ve got an animal with rain rot, it’s easy to treat and with some diligence, you can get rid of it yourself.
As you treat rain rot, make sure that you are also ‘treating’ any brushes, tack, halters or equipment that you use on your animals.
Do not contaminate unaffected animals by using equipment on an animal with rain rot and then an animal without rain rot.
Best treatment for rain rot
The best way to treat rain rot is with a shampoo intended for treating rain rot and following with a topical spray.
Many products that claim to treat rain rot are created to treat fungal infections. Rain rot is not a fungal infection, so make sure that the product you use has been proven to treat rain rot.
Wet the animal down and rub shampoo into the coat really well, covering the affected areas. Read the label to see if the shampoo needs to be on the animal for a certain amount of time before rinsing off.
When shampooing an area with rain rot, you can use a soft-bristled brush to gently scrub the affected area.
You can remove the itchy lesions and treat the brush at the same time. Just be sure the bristles are thoroughly shampooed and rinsed well so that they don’t harbor any spores that could later cause infection.
After the animal has been shampooed, rinse the areas off really well. Then use a scraper to remove as much of the moisture from the hair as possible.
Cover the affected area with a topical spray intended to treat rain rot. Most topical sprays recommend using them for 10 days to ensure the infection is gone. Keep treating the area and equipment after the rain rot appears to be gone.
I’ve seen that a lot of people try to treat rain rot with antibiotics. This is an expensive route and most veterinarians now would tell you not to use antibiotics to treat rain rot unless absolutely necessary.
The antibiotics can disrupt the natural micro-ecology of the animal’s digestive tract unnecessarily but also contribute to the broader problem of antibacterial resistance created by the overuse of antibiotics.
I recommend the following treatments for rain rot:
- Ring Out Shampoo followed by Ring Out topical spray by Flextran
- Shapley’s M-T-G original treatment oil
I’ve used both of the above treatments and I’ve been able to treat numerous cases of rain rot on horses, cattle and goats.
Both treatments work exceptionally well. With that being said, there are some notable differences between the two.
Shapley’s M-T-G is a product that I used for years with my horses. The M-T-G stands for mane-tail-groom. It helps to promote hair growth, which is an added benefit when you’re dealing with show animals or, in my case, horses that you’re preparing for shows.
Although Shapley’s M-T-G does seem to help hair growth AND it gets rid of rain rot, it does smell bad. It’s greasy and when you rub it into the affected area, it gets on your hands. The smell tends to hang around for a while even after washing it.
I recently tried the Flextran products and I was so excited that they smelled GOOD. There was no terrible after smell and I didn’t have a lingering bacon-flavored dog treat smell on my hands. It was also really effective at getting rid of rain rot.
Home remedies for rain rot
I use the above treatments for rain rot on my animals, but I have seen other people use home remedies to treat rain rot on their animals.
The most successful treatment that I have seen for rain rot is messy, but works. Mix the following ingredients together in a bucket:
- a 16-ounce bottle of mineral oil or 16-ounce bottle of baby oil,
- a 16-ounce bottle of 3 percent USP hydrogen peroxide,
- and a half-ounce bottle of tincture of iodine in a bucket
Do not mix these in a sealed or closed container. The mixture bubbles and will explode in a sealed container.
Use the mixture to sponge onto the affected area and gently rub it in. Leave the mixture on the skin to dry overnight and wash it off with a gentle shampoo the next day.
This mixture works in a few different ways.
The oil helps to recreate the natural barrier of oil that prevents the spores from entering the skin. It also soothes the itchy skin.
The hydrogen peroxide lifts the scabs from the skin, while the iodine and hydrogen peroxide work together to kill the bacteria.
I have seen people mix concoctions with bleach or alcohol, but these are rough on the skin and can cause additional dryness and itchiness. The dry and itchy skin can open up for more rain rot to infect it.
Preventing and Treating Rain Rot
The easiest way to treat rain rot is to prevent it. If you are purchasing new animals to bring home, it’s always a good idea to treat them like they might be sick. This includes treating them for rain rot.
If you treat them as a precaution, you eliminate the chance that they could pass rain rot to any animals that you already have. If you can, shampoo animals or use a topical spray on them before they step onto your trailer to bring them home.
Clean the trailer or cage that they came home in after you get them home.
Keep animals out of the rain, especially during extended rainy periods. Check your animals frequently for signs of rain rot.
As soon as you notice that an animal has rain rot, treat it. Continue treatment even after the lesions have disappeared to make sure that the rain rot is gone for good.
These treatments will work wonders to get rid of rain rot:
- Ring Out Shampoo and Ring Out topical spray
- Shapley’s M-T-G original oil
- Waterproof blankets, not water resistant!
- Insect repellent for livestock
If you want to make your own treatment, mix these ingredients together in a bucket and sponge onto the affected area:
- 16 ounces mineral oil (or 16 ounces baby oil)
- 16 ounces 3% hydrogen peroxide
- 0.5 ounce of tincture of iodine
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How do you prevent rain rot? Have you ever had a case of severe rain rot? Tell me about it below!