Hen with constricted pupil thin and dirty, feather loss red underbelly

[arpyhh]

I have lost three 2yr old red sexlinks in the last few months. Two in the last week!
Symptoms before death were significant feather loss on the underside, tail feather broken and brittle. Red rash on skin around vent and underside.
Filthy feathers, not grooming
Thin
A lot of thin shells lately
One had a droopy comb and nasal clogged just before she died.
Had the last one sent for necropsy and the report suggested peritonitis.
I am giving the flock antibiotics the vet gave me in their water. On second day of that.

Today I discovered another red with similar appearance but what made me look
Closer was her pupils are really constricted!
I brought her in, gave her a bath and blow dry, noticed scabs on both feet, so I pulled them off put antibiotic ointment on them and wrapped them up.
I made her a scrambled egg with some antibiotics in it and she gobbled it up. Had a couple very healthy looking poops.

Any ideas what's happening??
Thanks!

 

[Eggcessive]

The constricted pupil looks like pictures of ocular Mareks disease that I have seen.