A bad case of fowl pox, I think

[Eggcessive]

Here are a couple more articles about fowl pox and vaccination to read, since you live in such a common climate for the disease:
http://edis.ifas.ufl.edu/vm021

https://www.hyline.com/aspx/redbook/redbook.aspx?s=5&p=35

 

[ShellyBlanco]

Wow, after following and reading the links, this is a nasty virus that keeps on giving. Poor chickens.

 

[Robert G]

My flock is going through it now. We had lots of rain the last 4 weeks and one hen started, then another, and another. Of course she is the worse one now, but she eats and drinks well. They also free range all day. The sun finally came out yesterday so hoping it will start to dry out the wet ground and warm things up a bit. It's the waiting game for now.