Head Bobbing/Lethargic/not eating

[Bessetti]

My 8 week old speckled Sussex is bobbing her head, refusing to eat, acting very sleepy, and acting very abnormal for herself (she wouldn't eat treats and let me hold her without complaining).

Few outside factors to consider:
-it has been cold and rainy the past few days. They have a heat lamp on during the night outside.
-I haven't supplied grit because I assumed they could use the sand I provided for their dust bath
- I havnt wormed them

Any thoughts/advice? I really could use help ASAP because the last time I noticed a chicken acting out of sorts it died within a few hours. (Coccidiosis, all of them have been treated and given the prevention).

Thank you so much in advance!

 

[Eggcessive]

What did you use for treatment of coccidiosis, and when? It sounds like your chick may have cocci. Sometimes they need to be treated at 3 to 4 week intervals for prevention until they develop a tolerance somewhere between 11 and 20 weeks. With Corid, treatment for 5 to 7 days is usual. And you can treat for an additional 5 days with 1/3 the treatment dose.

 

[Bessetti]

It was actually my bantam flock that was treated- the full sized flock that she is in was vaccinated. Will the treatment null the vaccine?
'The most prominent of her symptoms is the head bobbing- she's doing it every few minutes and I don't know how to describe it otherwise. The chick that died from cocci acted very differently, could it still be that?

 

[Bessetti]

This morning she had more energy but was still tame, head bobbing, and not eating. Her crop is extremely full.

 

[enola]

You need to remove the food from her pen to see if her crop empties.