I have to disagree with Croyza being untreatable and the coop/grazing areas being unsalvagable.
I will start with a disclaimer that I just do what feels right and what has worked for me over the past year and a half of chickening, and I've run the gammut. My first chickens came as a full package for $5 each with upper respiratory infection, ingrown claws, mites, scaly leg and so on. I introduced some birds from another flock who carried Mereks, had Cocci take over my brooded hatches and fought croyza on a couple occasions.
Croyza is a fancy way of calling out the culprit in a cold. By the time you see a chicken is sick, its been battling it for a while. Croyza, like Cocci, requires good gut flora in order to maintain their immunity and build up their resistance and I use a few, relatively cheap things to do this. I've brought birds back from the brink. If they won't eat, give them a dropper full in the beak and they'll usually eat in the morning.
Add to their water: ACV at 2tbsp per gallon. The ACV needs to be RAW and UNFILTERED (Braggs is organic, raw and unfiltered) as it must contain the Mother. It's a natural anti-biotic and assists in reducing their odour.
Get yogurt and keep it on hand. Even if it seperates, if it doesn't have mould I give it to the birds. I get the yogurt which contains only milk and bacterial culture, no pectin, no preservatives. Just. Yogurt. To a container, add 2 dropper fulls of Oregano oil. Yogurt promotes natural gut flora in everything it eats and this one ingredient alone can save dying chicks who are falling apart from coccidosis. You can also dilute the yogurt in the water, just remember to clean it out after. Oregano oil is a natural, highly potent antibiotic and painkiller. And the birds love it when mixed into things.
Lastly, pick up Aloe Vera JUICE. Per one cup of the above mixture, ad 1tsp of Aloe Vera Juice. AVJ is a natural system flush in humans and animals. IT encourages movement in the bowl and helps to clear out the system of negative bacteria and increase flora levels in the stomach.
The above is the same principle I use to treat almost everything I've had here. As with humans, good gut flora makes for healthy critters.
Getting your chickens to a stage where they are resistant to exposure is what matters, and getting them over flareups is how I feel you can do that. Any chicken with access to the outdoors is bound to catch anything and everything from wild birds flying through the area and shedding dander. From experience, I feel Croyza is one of those "Well you have it now" things, and all you can do is raise a flock that can withstand the conditions of your area.
I'll probably take a lot of heat for this, but I look at sick chickens the way I look at kids: if we stop trying to hide them from every illness, they'll defeat it on their own. I don't set up a quarantine area when my birds are ill or when I'm going from coop to coop, as it's illogical to me -- wild birds will pass it on if I don't. New additions (from auctions or whatever) are the only ones who get an observation period. If I feel a bird needs to seperate itself so it can worry about being a chicken rather than it's rank in the pecking order, I will put them in a breeding pen for a week, which is still in the same coop. In nature, sick animals naturally segregate themselves when ill or weak and seek out the vitamins and minerals they need in the wild, be it certain grasses, herbs, bugs or whatever. This is why we give mineral supplements or oyster shells "Free Choice" to birds and other livestock. If cattle aren't lacking selenium, they won't touch the block for giggles, and if chickens need more calcium, they'll choose oyster shells over grit any day. They're smarter than we give them credit for. Providing treatments like the above is just my way of offering vitamins and minerals they can't graze for through 3 feet of snow or in my general area.
I hope this helps and gives hope. Best of luck, message any time.
