Chicken with feathers missing!! Help Please!!!!

[kathnkyle]

I have a chicken that is 26 weeks and the last few days she has been unwell and i noticed yesterday that all round her bum and some of her back her feathers are missing and she has a few small red marks on her skin!! she seems to be eating ok but i think she may have the runs as there is soft watery poos in the run but she does share it with 3 others!!
Does anyone have any ideas what it could be and what i should do to help her!!!
Many Thanks
kath x

 

[Farmer Kitty]

Separate her if you can. That way you can tell whether or not the runny poo is hers or not. Plus, if the others sense something is wrong with her they may peck at her.

Does she appear to be straining/squating like she maybe egg bound?

 

[kathnkyle]

She seems ok really other than that altho im only getting 3 eggs a day rather than the usual 4 (1 from each chicken) so I wonder if its her not laying!!!