Have you researched Deplumming Mites?
https://tvmdl.tamu.edu/2020/10/05/depluming-mites-in-birds/
I have no experience with these but have seen posts here on BYC about them. This could be your birds issue. There are other sites online as well if you search. Also use the search feature here on BYC.
What do you think @Eggcessive ?
If you treat for any type of mites make sure to clean out the coop and treat it also. Mites will hide in bedding and on roosts as well.
https://tvmdl.tamu.edu/2020/10/05/depluming-mites-in-birds/
I have no experience with these but have seen posts here on BYC about them. This could be your birds issue. There are other sites online as well if you search. Also use the search feature here on BYC.
What do you think @Eggcessive ?
If you treat for any type of mites make sure to clean out the coop and treat it also. Mites will hide in bedding and on roosts as well.