Definitive treatment for depluming mites?

[Hawana127]

My girls are missing feathers with bald spots and have mangled feathers and have poopy butts. I’m 99% sure it’s from depluming mites. I’ve been doing some research on how to treat this issue. And no one seems to suggest what an effective treatment solution would be and then followed up on what the results were and if they were able to eliminate the issue. I’ve tried ivermectin pour on and that’s really it, but still have issue. The full size Elector PSP is just too expensive for me right now so I have a 9ml bottle I bought from the chicken chick but haven’t used it yet. Is permethrin more effective? Dusting or spraying? I don’t want to keep cycling through ineffective treatments that don’t work and waste money. Any guidance would be greatly appreciated. Thank you.

 

[nuthatched]

Can you get pictures?

 

[Hawana127]

Here’s pics, they are pretty camera shy.

 

[nuthatched]

Looks more like they're being picked.
What's their diet?
Area size for how many birds?

 

[Hawana127]

Looks more like they're being picked.
What's their diet?
Area size for how many birds?

They are on 20% protein layer feed with scratch grains and BSFL for treats. I’m pretty certain it’s the depluming mite problem. There are two other birds in the flock that look worse than this. Those are just two pics I could find quickly for this post. 20x20 ft of run space, 7 birds. and they free range in the afternoon. I’m looking for mite treatment options that will work. So Im not wasting money on product.