Is this depluming mite? Pic included

[Sue Gremlin]

@Sue Gremlin is this the pic you mean with giant egg?

Yes! I see this is a photo you found online. This is not the same species of mite as the ones you photographed from your chicken.
I do not believe that what you show us here is a parasitic mite. There are countless environmental mites, just to confuse us, that chickens will eat, come into contact with, etc, that will show up in stool samples. I had an experience last year with mites in the feces and traced them back to mites in the feed. When I looked at some feed under the microscope, it was filled with grain mites.

 

[Trux]

 

[Sue Gremlin]

The diagnostic bits of a parasitic mite include the ends of the legs, (look at the feet), the hairs coming from the butt parts, where the anus is relative to the rest of the body, (middle, back?), and the shape of the mouthparts. Also how many legs are forward and how many are in the back. There are many, many others, but these are the most basic ones.
The pretarsi (toes) of a parasitic mite (this one is psoroptes)-note the bell-shaped pedicels:

Other structures to look for:

Most mites aren't parasitic. I have to keep reminding myself of that whenever I see them.

 

[casportpony]

Orally or topically?
More details on your treatment regime?

When I use it for leg mites or lice I use the 1% injectable orally.
http://veterinarymedicine.dvm360.com/knemidocoptiasis-birds

 

[aart]

Will remember @Sue Gremlin - Entomologist!
Those pics are great...where did they come from?
<Grumbles about lack of magnification notation>

I had grain mites, used scope to ID:
https://www.backyardchickens.com/threads/grain-mites.981212/

 

[Sue Gremlin]

Will remember @Sue Gremlin - Entomologist!
Those pics are great...where did they come from?
<Grumbles about lack of magnification notation>

I had grain mites, used scope to ID:
https://www.backyardchickens.com/threads/grain-mites.981212/

Parasitologist! I got them from Googling with "pretarsi of psoroptes" or something like that.

 

[Wmaddox]

I had a hen with depluming mites. It started on her face and she would scratch it and scratch it until there were scabs on her face. Eventually the bald patch extended most of the way across her throat and around the back of the neck, and she was a bearded polish, so she looked terrible. She would take one step then stop to scratch, one step then stop to scratch.

It baffled me for a long time because I couldnt find any sign of the actual mites and none of my other chickens were affected. I finally treated with ivermectin drops for several weeks as the three week recommend course wasn't enough, and it worked. She grew all the feathers back in the end.

How many weeks did you treat and how many days apart for each treatment?