I think it is Blackhead because of the dark blackness on her comb and feathers on her head. It is a bit sticky. I have been treating with the Fish Zole(since 7/25) and had one other hen(RIR) with the blackness coming on her too(7/26 started treatment). Both are getting the fish zole daily, both are older matriarchs at our house and pets. I don't think a vet visit is in the cards.
We started giving them scrambled eggs and they scarfed it up on 7/27. I am hopeful because they are eating again with eggs, broccoli, and now their chicken pellets crushed. I will get a picture of the poo to post. It is still watery and dark green and frequent, but maybe with the increase in eating it will improve in appearance.
My next move is to worm my flock again with Valbazen. I used Ivermectin horse paste on July 3 and 13th. Because of the Blackhead, I was worried that they have cecal worms that weren't caught that gave them the blackhead. The buff is thin, 1.5kg, and shakes her head more than usual.I don't want the cecal worms to perforate her intestinal tract and then deal with peritonitis. So happy they are eating again. No weight gain on the scale yet. Hoping they DON'T have a secondary infection like cocci or e. coli to deal with. I have a microscope, wish I was trained to be able to identify it reliably.