I need some help please. I have a Plymouth barred rock hen, Wilma, who is approximately 1 yr old and she is exhibiting symptoms of Marek's disease. She doesn't want to stand and when picked up/put down, she will balance herself with a wing. She will eat only the meal worms, not her normal pellets and I'm not sure if she is drinking on her own. I have been assisting her hydration with a dropper full of probiotic water. I've checked to see if she is egg-bound but I did not find any lumps in belly, but I'm not totally sure. I'm rather new to keeping chickens.
I've done some research on this website and others and the Marek's disease seems to fit but I don't want to rule out other possibilities, such as mold poisoning. She has been removed from the flock (9 hens counting her). 6 of the other hens are <6months old but appear healthy on all counts; the older hens too. Wilma is essentially the Queen so it's not likely that she is getting picked on.
These symptoms have been going on for approximately a week now, with no real signs of improvement. However, just last night I noticed she was "gasping" as though she was trying to get some air. I have checked her comb and it looks normal (no bluish tint) and her iris appear red in color, not cloudy. She is my little sweetheart of the bunch so I'm really trying to find some help for her. I understand that some of the Marek's cases last ~5wks so I'm prepared to nurse her along if that's what it takes. One last thing, I have not given her a bath as treatment for being egg-bound but I am willing to do so.