Apparently I need to dust for mites or lice. I never see them. One chicken ("Duck" the CX) has a bare rump though. She's actually had a bare rump for quite a while honestly. I just thought there was some weird molt issue at first. I have checked her a number of times for bugs. I never see any. I do see redness of the skin though. I researched this more today and all signs point towards mites or possibly lice. I think lice would have spread to the humans around here by now, so I'm putting my money on mites. I am booked all day 9-5 the next two days. I'll have to try to get to Farm and Fleet in the evening or get DW to go. So annoying! Good news is the other chickens do not seem affected. I don't want things getting worse though. I'll need to check the dust bath too. They like to dust bathe in the dry dirt a lot, but I keep an old tire filled with ash, dirt, sand, DE and whatever else I add for them to dust bath in just in case.
Lice can be species specific, so you probably wouldn't catch lice, but they are bigger, so you might see them. My guess is mites. You rarely see mites unless there's a huge infestation or you've got a bird that's not dust bathing - like a broody hen or weaker chicken. Either way, it's the same treatment. Although I do not see mites, I suspected it here.
For my birds, it started with poopy butt. (It's an orp thing.) As we washed each chicken, I noticed some had red skin and a couple had ratty-looking tummy feathers. Rooster feather damage is usually the head, back & sides of the hens. I know a couple people who are currently battling mites, so I suspect the weather this year may be the reason for the increase.
While my chickens were out in the yard on Saturday, I removed all the old bedding, feathers, spider webs, etc, then did a deep scrubbing, permethrin coop spray and DE after things dried before adding the new bedding. I also did lots of chicken baths and dusted them when dry.
TIPS:
* During/after the bath when the hen is wet, it's easier to inspect skin and feather shafts for mite damage.
* Chicken baths on a hot day help cool off chickens. Also allows you to keep chickens outside and prevents the need to blow dry.
* Easier to dust chickens at night and with a partner.