Yes those are pretty advanced scaly leg mites. I would bring her in and soak her legs in warm Epsom salts or soap water for 20 minutes. Try loosening scales with an old toothbrush or rag. Dry well and apply a good coating of either vaseline, mineral oil, Vicks salve, or Nustock cream every other...
Welcome to BYC and sorry about your sick hen. How old is she? Has she normally been laying eggs with hard shells recently? It sounds like she has a reproductive disorder. Dirty vents and diarrhea can be common. If you can get a good picture of her droppings that might be helpful. Do you have...
How old is she? This looks like the hen you have posted about a couple of times recently. It was hard to tell if it was gout or possible mycoplasma synovitis. Is there any way that you can have someone hold her upright so you can get a picture of both legs and feet standing? She sounds rather...
Breast blisters or keel abscesses can occur basically like a pressure sore on people. She may be lying down a lot on bedding that is wet or soiled, or she might have a rough roost. If she is lying around a lot due to not feeling well, that may be the case. You can apply povidone iodine/Betadine...
I really hope that it is not ILT. ILT is a virus, and antibiotics cannot cure it. Some cases are milder than others, but it is contagious. Could the blood be from injury or pecking? University of Guelph has a necropsy lab and testing available.
https://www.uoguelph.ca/ahl/services/necropsy
Yours has no long tail feathers or saddle feathers yet, so I think hen as well. Here is a guide on telling a rooster from a hen:
https://grubblyfarms.com/blogs/the-flyer/how-to-identify-a-rooster-vs-hen?srsltid=AfmBOoqYxcliHZVMeK1hdeRmv2zLldu-caTbR91AUpYc4_nyRrhmYjmf
Is he able to eat and drink? I would offer food and water. Here is another good link to read:
https://extension.psu.edu/infectious-laryngotracheitis-ilt-in-poultry
If you need to get a diagnosis if he dies, here is a list of state vets to contact...
You can bring home a chicken that looks perfectly normal, but could have been exposed to a sick bird and be a carrier. That is why most people quarantine new birds for up to a month to watch for any symptoms. Symptoms of ILT may occur 1-2 weeks after exposure. How long since you got a new bird...
Are you giving the E and BComplex supplements to the first pullet? She looks very weak and rubber legged. I hope it is not a sign of Mareks. The second one has a cough or sneeze. Is that also what the first one did? Have you added any new birds recently or has anyone with their own flock been...
Has she ever laid eggs yet? Her tail is lowered which means she is not feeling well or could have a reproductive disorder. Was the black dropping sticky? That is not normal although it could be really dark cecal poop if it was sticky and soft. What does she eat? I would try to get her eating...