I feel like I’ve tried it all, my gelding gets it so bad on his back legs, I’ve been washing at least every other day with a medicated rain rot/skin disorder soap which says to leave it on for 10 mins then rinse - any other remedies to battle this before it gets worse? I’ve tried a lot of stuff - mtg, listerine etc.

I am in South Georgia--capital of rain rot. I use the yellow bottle of Corona fungicide spray stuff from Tractor Supply.

I used shoo flys very successfully last year. They all started with bad bad rain rot/scratches and I got it cleared up in a week or so, never to return, even with our way record breaking wet year. 

I started putting coat defense on mine daily as prevention.....we shall see if it does any good. My daughter's little old mare is super prone to rain rot. 

Betadine! That has worked wonders for us in the PNW. Betadine bath, and let it soak for a while before rinsing  =]

Rain rot isn't a fungus, it's bacterial. Betadine works good.

I used mane and tail pro-tect medicated spray and it cleared my guys up nicely.