Mites? Molting?

[Chickenlady805]

Never had any issues up until now): notice my oldest chicken started losing her feathers around her neck and vent area. Shes the only one with this issue out of all 7 of my chickens. Shes been healthy other than this issue... her poop is a little watery?

I dont see anything crawling around her vent or head. I did change their food recently but im just hoping its not mites!

 

[Yardfulla poopers]

My guess, I'm sorry to say, is mites and/or lice. This time of year, it is not molting.
With feathers missing around the vent, it could also be worms. But I'm betting on the lice/mite combo. I have dealt with that before. I tried everything suggested anywhere (DE, permethrin, Ivermectin) before trying the Elector PSP which worked like a charm. We do annual baths in it now.

 

[Wyorp Rock]

Never had any issues up until now): notice my oldest chicken started losing her feathers around her neck and vent area. Shes the only one with this issue out of all 7 of my chickens. Shes been healthy other than this issue... her poop is a little watery?

I dont see anything crawling around her vent or head. I did change their food recently but im just hoping its not mites!

Vent is being plucked, likely the neck is too.

Observe to see who may be plucking at her.

Keep her vent cleaned up, you can apply a little NuStock Cream to the skin to help soothe it from poop and perhaps deter some of the plucking.