Could i have overdosed my beautifil girl on flubenvet help!!!

I have a sick little girl my ranger, she is always the life and soul of the hens such a great girl and so lively when i came home from work tonight she is half standing half sitting with her eyes closed with hardly any movement and usually she is flying round all over the place running to greet me...She was her usual self this morning at lunch time i gave her a dose of flubenvet and my other girls who are all fine they had a dose 2 weeks ago as they all had worms and one we thought had gape worm so was advised to dose again after 2 weeks. I have to give them there dose on a piece of fresh corn as they scatter there food everywhere and usually leave quite a bit so i measure it out and give them each 1 bit of there favourite corn with it on but i think ranger got an extra bit as my sussex dropped hers and ranger being ranger grabbed it could i have made her like this she looks very listless. I have just had to have some 10 week olds i hatched from chicks sent up to chicken heaven as the breeder i bought them from thought it could have been mereks disease but thats another story i was so upset they are all in seperate runs not free ranging with the rest just yet : it does not look like the symptoms they had can anyone please help me is it possible she could have overdosed i have heard it is hard for this to happen im feeling so bad she is one of my favourites, well they are all favourites i love them so much but am feeling with the run of bad luck im having my heart can not take the sadness and am really thinking hard about weather i can do this anymore...please advise.

Thanks aunt sally, she definatly had a double dose of flubenvet all at once  im feeling terrible at the thought it could be me who has made her like this 

Hi there i give them it once a day for seven days that was the first time they had had it as they are all under a year and now im giving it again after 2 weeks this was there 2nd day...its just so not like her she looks like she is just falling asleep standing up and very slow movement she has not missed a day egg laying since she started laying and layed one this morning. Its just very strange she was flying around as usual this morning had medicine at lunch time and when i came back 4 hours later she was just tucked into the wall NOT at all like her. I have just put her into bed im almost frightend for morning to come as i will be to scared to open the door in the morning incase anything has happened to her. Her last poo before bed was like a clear liquid looked quite slimey  with white in just a little one though and she had some water and a little corn i will just have to have a very restless night and see what the morning brings

Casey thankyou so much you were right about the soft shelled egg i went out this morning and opened her door and she came trotting out as usual but under her perch were 2 very soft shelled eggs i dont know how they hadnt broken falling onto the floor but why 2 is this unusual or quite common??? She looked back to her normal self she had food and water then went back into her laying nest box i presume to lay another egg she is a hybrid and lays lots of eggs but i have never had this before do you think the next one will have a shell. Im just confused as i thought because she had layed everyday she wouldnt have any stuck i give them oyster grit and shells to eat and have just bought some vitamins with grit to add to there food to give them a boost but is also said it helps make strong shells, all of her eggs have been perfect to date. Thankyou for your advice i know i worry to much but i adore them all....

Thankyou so much for your help i thought i might have poisened her with the flubenvet, so happy now 

I was so happy today that my girl seemed back to her usual self after passing 2 soft shelled eggs last night, but she is doing the same thing again surely she can not have more soft shelled eggs to pass, can this happen? She seems really listless and looks as if she is falling asleep i thought that would be the end of it as she looked back to normal today and is it normal to pass 2 at the same time like she did, i will have to see what tonight brings and see what she leaves me in the morning....

I have a Bovan Goldline which lays soft shelled eggs, sometimes one double yolker and other times two soft shelled other times one soft shelled with two yolks and one with no yolk.  Their does not seem to be a pattern to it as I keep a diary.  It is worrying when it happens two days in a row but she recovers straight after laying.  She is about a year old but has done this from us getting her at 20 weeks old.  People say it is common in older hens when they are finishing their laying career.  As long as you are sure there is no egg remaining in her that has not been laid successfully she should be fine.  If you think she still has some shell or egg inside you can do as Casey76 said about the warm bath which should help.

Good luck and keep us updated.