Strange scabs/ lumps on horses

[Foxlover46]

Hi I was wondering if anyone can possibly share any knowledge on this before my vet visits on Friday
My horse has got strange under the fur tiny lumps on his back end , it feels like little circular scabs down each side of his bum to top of his flanks but he doesn't have mites I've checked and then I've lifted his tail and I've seen these two bumps
I'm not sure what it could be and obviously worried
Thank you if you have any ideas

As he is grey I would get vet to check whether they are melanomas. Key place to get them

Oh goodness me , I hadn't thought of them! Thank you so much the vets coming on Friday

If you pick at it does it come off in crusty yellow scabs with bits of hair attached?

If so it prob rain scald/mud fever. It's caused by a bacteria in the soil & thrives in damp conditions (hence the name rain scald) They are different names for the same thing - rain scald on the body & mud fever on the legs.

One of mine gets it around this time of year. Advice is to remove scabs with warm water & dilute hibiscrub (follow dilution instructions as most people make it too strong which damages skin) then dry as thoroughly as possible. I use Lincoln muddy buddy cream

@Serencwtch thank you , I was googling to see if it could be rain scold , the scans are exactly as you described on his sides , I've picked up some hibiscrub and ordered the Lincoln much cream. He never got this last winter , I'm gutted.
Thank you so much

@Serencwtch *scabs sorry

Mine seems to get it some years but not others. This autumn has been wet & mild so prob made it worse. If I get on top of it when the scabs are quite small it seems to stop it spreading.

Wash the cloths & towels you use on a hot wash to kill the bacteria otherwise you keep spreading it.

Vet also said to make sure the area is thoroughly dried - even said some people use a hair dryer.

Keeping the coat clipped & not over rugging also help (I was inadvertently making it worse by rugging her as the name 'rain scald' implied it was caused by being wet when actually sweating is worse)