Missing Feathers/possible illness

[zs14]

Hello all,
We got our chickens a bit over a year ago, we have 25. I have not been home all year, so other family members have been caring for the chickens. I was warned that one of the birds named “my friend” was bullied pretty badly. Anyways, upon my arrival back home, I waited for night time so she’ll be steady on her perch so I could examine her, and she looks horrible. I think the problem is more than an average case of bullying.

As you can see in the pictures, her whole back and rump are bare, with the top portion being extremely red, probably from others pecking. The reason I worry she is suffering further is the way she sits on the perch, and her vent’s in and out motions. I don’t this these are normal for a chicken. Perhaps, she is suffering somehow, which caused her to be bullied?

Additionally, I think the birds are molting, which seems to be worsening the issue. I have other birds who are bullied, would you advise separating them? My issue with that is it will probably take months for her to grow the feathers back, and reintegration may be a issue.

I would greatly appreciate all suggestions. Thank you!

P.S. here is the link to a short video of the pulsation of the vent.

 

[coach723]

Do you have roosters? 25 birds in how much space? Do you know how old she is and if she is currently laying eggs, or when she last did?
What do you feed, including all treats? Is she eating and drinking normally? What do droppings look like? Check her crop to see if it's empty, full, hard, soft and squishy. First thing in the morning before she's had feed or water it should be empty. Feel her abdomen to see if it feels bloated at all, hard, or water balloon like. Compare with other hens if you are not sure.