I have raised chickens for years now. Literally hundreds of chicks and I feel like I’ve come across my fair share of issues. But all of them I raised were back in Hawaii. I am now in the very Northern edge of Georgia going into Tennessee. And I have lost 10 chickens out of my flock of 22 slowly. It is a mixed flock of rare breed (an assortment from Murray mcmurray) they are now 20 weeks old. They all seem fine then one day I’ll notice one is looking a little ragged feathered, next day it’ll be fluffed up. Some have been a little stumbly while they go down hill over the course of a couple days and then it’ll die. One at a time over the course of the past couple months. Only one day we had a few die at once. Every other instance has been one at a time. I’m stumped. I’ve treated for coccidiosis a couple times spread apart. I’ve done vitamin b in the water. I haven’t seen any dark or bloody stools. They have an enclosed area of the coop they can hide from weather, get time free ranging but also have an attached run. Access to water outside of the sleeping area, which has a roost, door we close when it gets too cold and pine shavings. We are just stumped But I’m wondering if it’s mareks? Or something like this. I should mention when they transitioned outside at 7 weeks, I thought they had gotten a case of fowl pox cause they all had the black spots but that’s seemed fairly mild and no one has shown any external signs of illness since that cleared. Could that have been a first sign of mareks? Thank you for any advice/guidance. Thinking of driving the 100 miles to get of necropsy done so I can stop losing all these chickens