A sick Ancona

[rollo4]

I have 3 chickens: 1 Ameraucana, 1 Road Island Red, and 1 that looks like a Ancona.
It's the Ancona look-like that is sick. This morning she was not in the coop area when I brought them food. She's always there and is the biggest eater and more aggressive. She was in a roosting section inside and did not come out even after setting down the 3 platters of food. About 30 seconds past and she came out only to shoot out a spray of poop and then proceed to peck out a small tail feather of the Red and eat it. She did the same thing the day before. This is the first time I witnessed this type of peck. She's very quite now, does not eat, and is mostly inside.
I let them out in our backyard to roam around regularly. There's nothing there that's dangerous for them to eat. Yesterday she acted normal.
I'm fairly new to this, since April, 2013. I acquired them through a friend. They are around 2-21/2 yrs. old. I have not had any problems with them until now. Should I wait until tonight or tomorrow to take action? If so, I have no idea what to do since I have no idea of what's wrong with her.
Does anyone have any diagnosis and/or treatment? All responses are appreciated.

 

[Scrambled7]

HI there chicken lovers,

I also have what seems to be a sick Ancona. My girl is only 12 weeks old and was also very lively and strong and is now displaying very sleepy, lazy symtoms.

She is still eating (a little) and drinking, however she is not interested in foraging and is very quick to just stop and close her eyes.

At night she will still jump up the various bars to get up to her perch but is always the last out in the mornings.

Does anyone have any advice?

 

[seminolewind]

Rollo, see if your chicken is broody. Does she puff up and "growl"?

Scrambled, those symptoms and age would make me run for the coccidiosis medicine. Corid or Sulfadimethoxine, which you can find at Tractor supply and some feed stores. It can kill them quick. And there is not always tell-tale blood.