prophylactic medication for Coccidosis???

[Stormyweather]

Help!
I have a sick 12 week old pullet. She has been on medicated chick starter her whole life (the entire flock is). She has vague signs of failure to thrive, not eating or drinking, acts off balance and is slow. Falls asleep immediately anywhere she wanders. She doesn't stay with the flock. She is incredibly skinny. I first noticed her acting 'off' two days ago but this has likely been going on a while since shes so thin. Her crop feels normal and I can manually open her mouth, but when I syringed some water in the liquid just poured out of her. She pecks at the water and food but isn't swallowing anything. She doesn't look like she's going to make it.
I don't see any bloody poop anywhere.
I have seen others online say this sort of stuporous and anorexic behavior can sometimes be coccidosis. I bought Corrid and I can medicate my flock but SHOULD I? I have no confirmation this is coccidosis. I would be devastated if I lost my whole flock due to this. We are in Georgia and I have heard its been a terrible year for this disease.
I feel like I have to act quickly as this disease spreads fast but I just don't know what to do. The county extension office was no help and I've been waiting most of the day for a vet to return my phone call.

 

[Justso]

Sometimes there is no bloody poop. I just lost a chick to coccidiosis and I'm heavily treating the next one. Unfortunately I missed the Hallmark signs with the first one, it was too late. since she's young I have her separated and medicating her separate, but when she goes in with the flock I will treat water for the whole flock. I see no harm in this.

 

[Chicalina]

if she is on medicated food already, then i cannot see any gain in giving her more meds for the same disease, and it could harm her.

Look for other possible causes, like worms?

 

[Eggcessive]

It would not hurt to give her a course of Corid at 2 tsp of the liquid Corid or 1.5 tsp of the powder per gallon of water for 5-7 days. Corid is pretty safe to use, even for your other chickens. Make aure that she is drinking the Corid water. In addition, you can give 0.1 ml per pound of the undiluted Corid twice a day to boost her. After treatment, give her some chick vitamins.