Oh, I'm glad she was able to lay an egg!
If any tissue is still swollen and protruding, then it would be "prolapse". Sometimes it can be severe, other times, not quite as bad. It's good to keep the tissue covered with your ointment and continue the calcium.
If she's not lethargic, soaking in a warm(ish) epsom salts bath can often help reduce inflammation and swelling too. I say warmish because if you are in the U.S. it's likely HOT. I've found that when it's hot weather, giving a warm(ish) to cool soak is often well tolerated.
O.K. I should have asked where that wound was located on the body!
So it's under the wing on both sides?
When you can, take some additional photos in context so we can see the location better and if you have 2 other hens with similar injuries, some photos of those too.
Even though you don't have a rooster, do you have a hen that is mounting the other hens? Does she have spurs or sharp nails?
Sometimes another hen can mount others and it's not uncommon for a hen to have spurs.
ANY Chance you do have an incognito rooster?
ANY chance something could have grab them, fox, dog? It is strange to have 2 with similar injuries I agree.
To me in the photo it looks like injury.
You are right to worry about flies, boy oh boy, flies and wounds are bad news.
Under a wing is a moist environment. I'd swab daily with Chlorhexidine if you have it, trim feathers away from the wounds to help keep things a bit tidier and easier to clean.
I would also consider getting some Swat and apply that around the wounds to help deter the flies. It's going to be a challenge since you have several hens to care for.
What antibiotic do you have? IF they are recovering o.k. and the wounds are healing up nicely, the medication may not be needed. If you note any bad odors, infection, etc., then you may need to treat.
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