Lethargic rooster

[Eggcessive]

Can you swab the ear for any drainage or gunk. Ear mites may not be seen without a microscope. If you are seeing respiratory symptoms that could be the cause of ear problems.

 

[HappyClucker7]

Can you swab the ear for any drainage or gunk. Ear mites may not be seen without a microscope. If you are seeing respiratory symptoms that could be the cause of ear problems.

His ears are clear at the moment. They have been for probably about 2 weeks now. If they get worse again, I can swab them though.
I do have my own microscope. It's not the most powerful, but it does work pretty well. Could I use that to find mites if his ears get worse again? What exactly would I be looking for?
I'm not seeing any kind of respiratory issues.
If his ears don't get worse, and respiratory issues are not the cause, then what else could be the problem?