Strange illness

[LUVMYCHIKAS]

I have searched for a similar thread and can't find anything. My buff brahma hen [2 1/2 yo] is eating normally, drinking normally, poo is normal. She has NO respiratory symptoms at all. However, the black feathers that normally adorn her neck have recently vanished. She is not molting. She molted in June and her molts are not pretty. Again, this is NOT a molt. She isn't losing any feathers on the poop board at night...not one. It appears that just the black feathers are gone on her, but not her sister. Also, and may or may not be related, I noticed her head appears slightly swollen. Really there just appears to be some slight swelling around her eyes, but again, there are zero respiratory symptoms. No cough, wheezing, drainage, nothing. She otherwise seems perfectly healthy. I'm unsure of her laying habits because I don't catch anyone in the nesting box, but someone is laying several times a week.
Does anyone have any idea what's going on with her feathers and/or her swelling without resp symptoms? Any help would be great!! Thank you!!

 

[esme13]

Have you checked for parasites? could be a mite that's eating the feathers and causing irritation. Or it could be feather picking from the other hens. Hopefully others will chime in.

 

[Skylercarr]

It sounds like another hen is picking her feathers out. Do you have a rooster? If you don't sometimes hens will take the male role and try to mate with other hens and this can cause some feathers to be plucked.

 

[LUVMYCHIKAS]

I have checked for mites and haven't found anything. I thought about others feather picking, but it is so uniform that I find it doubtful unless I have some OCD chickens lol. I do have roosters. She is loved by Roo who has been her man from the beginning. Its very strange really! Thanks for your thoughts!