strange spots - any ideas

[Spangie]

My mare is on holiday with my gelding due to my health issues. To save my grazing, the 2 of them have been at a friends field. It's a big area, with access to some woods. Whilst she's been up there, she has developed some spots, which start off as a lump, then go a bit 'serum-y' then go bald and finally start to dry up. They are concentrated around her muzzle, so i think it might be something she's sticking her face in??? the gelding has nothing of the sort.

Has anyone seen anything like this? is it an allergy to a plant/Insect bite/something worse???
any ideas gratefully received.

i have now moved her back onto one of our fields where all she has is grass, no bushes/trees etc.... to see if that makes a difference.

 

[LynH]

I have 2 out of 3 with what sounds like the same thing on their faces, necks and legs. Theirs is rainscald from the dew and damp grass. One has had rainscald before but more severe than this, the other has it for the first time but it's his first time living out.
A few people I've spoken to have had similar problems for the first time this year.
Do they look like small patches of mud fever? Rainscald starts with serum/yellow pus clumps of hair that feels like a lump which when cleaned off leaves pink sore skin underneath.
Both of mine started on their faces but they've got a few come up on their legs.
I wash them with hibiscrub or ag silver wash and dry them before putting heel to hoof cream on.

 

[Spangie]

that's interesting LynH. Do you think some horses are more prone to it than others? This mare we've had since Nov, she came to me in a very poor state, years of being malnourished I would say. Could this have anything to do with it as my gelding is out in same conditions (same rugging etc...) and he's fine!

 

[LynH]

My TB mare was caught in a bad flood 10 years ago and lost lost of her hair to rainscald and has been prone to it since. I always assumed her skin was weakened by the first bout and I do have to be careful with her. The other one is a Welsh Sec A who has probably lived a very pampered life as a show pony and is living out for the first time.
It wouldn't surprise me if a weakened immune system from previous malnourishment would make a horse more susceptible to it. What has surprised me is that other people have had horses with rainscald this year when we've had less rain. My TB hasn't had it on her face like this before but I put it down to her being in a field with particularly long grass. Their faces get wet from the dew on the long grass. Has your friend's field got longer grass which would make your horse's face wetter than it had been at home?