Esther,
My baby Buckeyes are 4 months old and 2 have same symptoms in last 4 days. The first hen always by herself while others free range with eyes closed. Not eating or drinking. Not caring what noises happen around her. No other symptoms. Got worse within a day or two and seemed to be dying. I brought her in and fed her mixture of pedialyte, sugar, baby chick food, vit e capsules, and vinegar with a syringe. It was so difficult to get her open beak, but forced her to drink it. She became energetic after drinking 3ml, napping for 2 hr., and drinking 3 more ml of the mix. I put her back with the flock and couldnt tell within minutes which one she was.
Then, I found the most disgusting thing that I had ever seen. A large green dead round worm in my coop. Someone must have poohed it out. I treated with Wazine.
Then last evening noticed the top hen sleeping, not moving, not caring, and not foraging. I brought her in and did same. She was worse shape, layed down with face in bottom of cage. Had more difficult time coaxing and forcing the mix down her. I got 9ml of mix in her, then let her sleep all night. This morning she was up and peeking through the blanket on the cage. I made her eat/drink 9 ml more of the mix and took her back out. She ran out of cage and drank from their waterer for 5 minutes, then ate from the feeder. Seems like a little weak, but maybe she'll make it.
I don't know what symptoms of round worm are but only symptoms they had was lethargy, weakness, not moving, not eating/drinking, and not caring about noises.
Sorry about your chickens. I don't know if this is anything to consider or not but might be worth treating them for.
Tammy <3