worried about hen

[Wexford Chuck]

i am new to having hens and have recently brought 6 large pullets rirx but one seems under the weather, she doesnt stretch her neck out like the others and seems alot slower and lethargic, i started worming them could this be why she seems lifeless.
any help would be appreciated.

 

[Mrs.Puff]

Could be she got too much wormer, but probably not. Isolate her from the other hens, maybe get some antibiotics in her... Check her crop to see if she's got an impaction (she'll have a big ole' swollen mushy crop).

 

[Wexford Chuck]

will start building a quaratine coop and run in the morning, hoping she is more lively and moving about a little more. the wormer says i must mix into food for 7 days but im a little worried it might have an affect on my ladies.
would it still work if i stopped using it for a few days, to see if theres any effect.