You can't see Depluming Mites, they live under the shaft of the feathers and feed off blood. Treatment with Ivermectin is needed in order to eliminate Depluming Mites.
Northern Fowl Mites, you should be able to I.D. within the coop at Night and on the birds.
Same with Lice, you should be...
Can your vet run a fecal float to see if she needs deworming?
I'd check her crop to make sure it's emptying overnight. If she's having a hard time picking up feed, look inside the beak for any lesions or canker.
The yellow urates along with the blood clots could indicate something going on...
Looks like Lice Nits.
The eggs are basically "glued" to the base of the feathers. Are you seeing actual crawling bugs or lice on the birds?
To help unglue to the Nits, you can apply some coconut oil and they will start to come off. Some people pluck the feathers, but if there's a lot of...
Can you look inside her beak for any lesions, canker or mucous?
She has some crusty material on her beak and face, is that stuck on food or mucous?
What's her crop like? Is it emptying overnight?
How's the ventilation in the coop?
When was her last egg?
Any lice/mites?
A video of her...
Does she have lice or mites?
Her eye is a bit sunken which may indicate some infection or conjunctivitis in the eye.
The facial swelling, it's hard to tell if it's from picking/scabbing, bugs or respiratory illness.
Clean/flush the eyes with saline, then put an ointment like Terramycin eye...
Hi, do you see worms in the poop?
Taking a sampling of poop to a vet to see if the birds need deworming is a very good idea.
In the UK, for Chickens, Levamisole or Flubendazole (Flubenvet) are commonly used to deworm. Iirc, Levamisole can be added to the water and Flubendazole (Flubenvet)...
Once a hen has been separated out from the flock, often it's a challenge to reintroduce them, they can be viewed as a newbie or intruder. Once she's better, try a see no touch method like caging her within the coop or run so they can become more familiar with one another. The Top Hen is doing...
She has some minor Contact Dermatitis in the foot pad(middle circle), which I don't think I'd mess with much at this time.
What's struck me is there to the left at the webbing is a hole(?)
Can you investigate that?
That would be where I'd think it's most tender. Is that toe swollen too...
Hopefully she'll bounce back some, it's good that she's drinking now.
The poor girl, it sounds like she did need draining if she wasn't pooping and crop was very slow. The fluid build up can make it difficult for the body to function properly (as you know), so this is a good start to see her...
Unfortunately DE is not going to be effective against a heavy Mite infestation.
Ivermectin can be helpful, but the Mites also have to bite the birds in order for it to kill them since it has to be absorbed into the bloodstream for it to be effective. So that means more Bites to an already...
Looks like it could be lash material, hard to tell. It can be different shapes, sizes and colors.
I'm not sure what else it could be, hopefully others will chime in.
I would not treat any pullet with Baytril (Enrofloxacin) unless I was very sure she was the one expelling that material...
You have air conditioning in the coop?
Likely she's having a hard to acclimating from cool to hot.
Do not dunk her in water. Provide shade and cool water.
Can you get a video? Upload to the BYC Gallery or Youtube and provide a link.