My mare gets horrible skin fungus every summer. I think it is her own sweat that causes it - I think she just sweats out in the pasture, and then it starts itching, and she rubs herself until there is no more hair. There's a direct correlation between when the weather gets hot and when it appears - as soon as it starts to drop from the 100s into the low 90s, her hair starts to grow back.
I have been using micro-tek shampoo on her, and it is not really helping much. I am thinking of trying an iodine shampoo instead, and seeing how that works. Any brands in particular that work better than others?
We have someone at the barn whose horse is allergic to his own sweat. She does not use soap on him. The vet just wants her to rinse him down, blade him off and allow him to dry thoroughly before stalling him, so that's her routine. Iodine shampoo has a way of drying the skin, so I wouldn't use it if this is only an allergy. For fungus/scratches I like chlorhexidine shampoos with moisturizer in them. I personally like DVM chlorhexidine shampoo because it also has a light moisturizer to keep the skin from drying out. It can be expensive, though.
That is really interesting that you mention the chlorhexiderm shampoo! I have a chlorhexiderm solution I got form the vet for a mouthwash to treat some mouth ulcers (summer is not my girl's time of year!), and I figured since it was antimicrobial, it wouldn't hurt to put some on her fungus-y hairless areas. It seemed like it was helping her hair grow back, but then she had another break out ...
The chlorhexidine shampoo doesn't look any more expensive than the microtek, so it could be worth a try.
The vet has said the only way to eliminate this is to feed her a low does of steroid throughout the summer. I am really not into this idea...
She's an easy keeper - hay only (large pony in moderate work) - so changing her feed around is not an option.
One of my horses had MAJOR fungus issues on his back and hind end so badly we had to blanket him this winter because he would get chilly without his hair! I used Cowboy Magic Krudbuster religiously and a fungal shampoo. I alternated and it seemed to work really well. His back and hind end are now just looking great.
I have been using Tea Tree Oil shampoo- I got it at PetsMart.
My delicate little 18 hand ISH has been hivey most of the summer- this is really good stuff, especially if you have the concern of an allergic reaction (in addition to whatever you are already dealing with!)
Has quite a different smell! I have used MicroTek, Krudbuster, and I do like the Tea Tree the best.