It’s that time of year again, fuzzy winter coats and rainy days can quickly set the stage for rain rot. What is rain rot? Rain rot occurs most often on the back and rump and is characterized by matted hair and bumps which turn into crusty scabs and lesions. The area is often very tender and sore. Rain rot is caused by a bacteria that is in the soil, and so is also in our horse’s coats. When moisture gets trapped in the hair coat it creates a warm, moist environment that is perfect for the proliferation of the bacteria and that’s when we start seeing the bumps. Severe cases of rain rot are usually seen in horses that are underweight, or their immune system is compromised in some other way. However, even healthy horses can still get rain rot.
It is also thought that insects such as ticks and biting flies can spread the bacteria, so it is important to monitor other horses that live close to the affected horse. As with any skin infection, keep a set of grooming tools for use only on the rain rot horse.
So how do we treat rain rot? The first step is to keep the horse clean and dry. If the weather is going to be damp, bring the horse inside or at least put a blanket on him. You will also want to groom the horse regularly to keep working the scabs loose.
The first step of topical treatment is to wash the horse with betadine shampoo. Really work the shampoo into the affected rain rot area and let the suds sit for 10 minutes before you rinse it off. After the horse had dried, apply another treatment to kill the bacteria. There are tons of products that claim to be effective on rain rot. I have tried a lot of them on stubborn rain rot cases, and these were the two I found to work the best: Shapley’s MTG and Eqyss Micro-Tek spray. MTG is a greasy, oily product that you rub into the affected area and leave on. It will make your horse greasy and it smells a lot like bacon grease, but it is effective. Eqyss Micro-Tek spray is a liquid spray on product that has a watery consistency, so it doesn’t make a mess and it does work, but it is also more expensive than the MTG. A really low cost treatment that I have heard about but not tried yet is Listerine. Supposedly, you dilute the Listerine 50/50 with water and just spray it on. As I said, I haven’t tried this one yet but I plan to with my next rain rot case!
There is one other step I recommend for rain rot treatment and that is deworming the horse with an ivermectin paste. Because rain rot occurs more often in horses that are immune compromised and underweight, the deworming treatment will get rid of a possible parasite load. Ivermectin is also used to treat other types of dermatitis, so in case you have mis-diagnosed your horse’s rain rot, the ivermectin may help.
I have included links below for MTG, Eqyss MicroTek Spray, and Listerine (if you try this one, let me know how it works!).