Greetings
Hwy9fam,
Bacterial infections of the eye usually respond to ophthalmic antibiotic ointments. Stubborn bacterial infections, may also require an additional Broad spectrum antibiotic, oral or IM. But, they too will usually heal.
Sometimes, if infection has been untreated for too long, a dried pussy film may need to be removed. But, this is not as easy as it seems. A novice at this procedure, could injure the chicken's eye. Permanently blinding the chicken or worse.
However, if a fungus has invaded the eye tissue, this requires a completely different course of action.
How do you know what you are dealing with? You don't. We keepers start with the most common disorder first. Normally, it's a common bacterial issue. Virus's can also cause eye infections.
I am glad you are going to see a vet. They need to see the pictures of your other hens, and the black substance on them. Identification of the microbe is needed.
I could not advise you well enough, as, I am just a chicken keeper like you. I have experience with fungal skin infection on my dog, and yeasts on my rooster's comb, and most keepers have, or will deal with yeast in the chickens crop. Fungi/yeasts are just as deadly as any bacteria or virus.
Please update us, so that we can learn from this case.
I am thinking of you and your flock...
And, I will pray that all goes well!
God's Blessings of peace, and good health, to you and your flock.
