We recently lost a chicken due to unknown reasons. We noticed today that one of our chickens was behaving a little off. She keeps her walking limited, and her tail goes straight up and you can clearly see her vent is pulsating, like she is straining in some way. Her comb is bleeding as well (maybe she is getting pecked?). We have brought her into the warm house way from the other hens. She is in a large dog crate with water which she has been drinking from what we can tell. We have checked her comb and it is soft and squishy and we checked to see if there is an egg bound, nothing was felt. However we are still new to chickens and after having lost one recently we did use some olive oil to see if that will help if there is in fact an egg (maybe I didn't feel it?) just to be safe.
Any suggestions on what else could be the problem? What else we could do? She has no mites or worms seen. Clean vent so no diarrhea or anything like that. Maybe there isn't even something wrong other then her comb being pecked by the others. (There was some noise today and we thought maybe there was some fighting due to a new pecking order after we lost a hen?) Any suggestions would be appreciated.