Bald itchy patches where stifle meets belly?

[kellybee]

I have a little shetland mare aged 17, she's fully clipped (she was sweating so badly back in Oct) and wears appropriate rugs for the weather, but I brought her in last night to find she has little bald patches in the place where the skin is loose just where the stifle meets the belly. They have little tiny scabs like you'd find with mites though I'm pretty sure she doesn't have mites. Her face and exposed parts (neck and belly) have longer bristles so I'd expect her to have an itchy face if she had them but other then this I'm stumped!

Anyway, I took her rug off as always to check her over and she promptly turned around to scratch the patches with her teeth. When I say scratch, I mean she was like a pony posessed. I doubt she was too warm as it was 3/4degs and she was only wearing a lightweight. She isn't moulting yet, was wormed with Eqvalan duo recently and has no other marks/bald patches anywhere else. Any idea what it might be?

 

[Echo Bravo]

Get some louse powder and dust her over, this weather has been pretty bad horsewise, as 1 minute they are cold and wet and the next hot and sweaty just what the lice like.

 

[HappyHooves]

Why do you think she doesn't have mites? The response to having her rug off and the nice warm hidden place she is itching would make me suspect mites. You wont see them with the naked eye - try some sticky tape on her skin and see what you pick up. You'll need a powerful lens to see if they have legs! Though if its lice you can see them easily.
You'll need to treat all her rugs if its mites/lice, and shampoo her with Selsun ( diluted 1/10) and left on for 10 mins. If you can get some Deosect that's very effective against lice and mites. Easier at this time of year as you dilute it, and fine spray it on so no need to soak the little one. With a gloved hand you just rub it into the coat. Total amount is half a pint for a pony.