Yes I think a most of what our chickens can get comes from the wild birds.Since you mentioned coop/pen.. The wild birds have so many different problems. I think most problems can come from them..
https://www.backyardchickens.com/a/some-thoughts-on-general-coop-hygiene-and-ventilation
Duck eggs are the "secret" to why French pastries, cakes and other baked goods are so incredible. The duck eggs impart a wonderful texture and flavor to the foods they are added to. @CityFarm you are making me want ducks again. I had five muscovy ducks once a long time ago. They were fun but we ate them before they could lay.
This is a duck egg.. Our girls are not laying yet, but the eggs are bigger.. The ducks don't get sick, lice/mites.. Well, I know it sounds to good to be true.. They lay just as many eggs as chickens..
Oh &!!! Cheryl our silkie is BROODY again...4th time this year.. Unbelievable .. We put a few of our eggs under her.. But also, 3 isbar or isbar Swedish flower mix, 3 wheaten & 3 Golden cuckoo..![]()
Praying for a good hatch...

I call those long pointy eggs torpedo eggs. I have a Marans mix that lays them.I'm busted! Yes, long story, did an "undercover" name change.
Funny eggs. Look at the white egg, second from the right side. Got this crested Polish that lays these looong skinny eggs. (or, since this pic is on my non-cooperating cell phone, second white egg from the bottom!)
Pretty! So the Isbars are the green eggs?