Three Dead Chickens in Two Weeks?

[APanamaMama]

I lost a four month old naked neck chicken two weeks ago. Then Thursday another died. I found the first one dead, laid out. The second one my kids found, unable to walk, flapping around in the coop. It died shortly after. Now I have a third naked neck (unrelated to the other two) who I found standing in the coop this morning. She is three months old. She usually runs from me, but she let me pick her up. She is smaller than her other three sisters. She just stands there with her eyes closed. I syringe fed her some electrolytes this morning. I had given the chickens dewormer the other day in their feed. I have 30 chickens and live in the mountains of Panama. The chickens free range. This chicken I bought from a local feed store as a day-old chick in March. Attached is a pic of the still alive black one and dead red one. Any help is appreciated, but some stuff is not readily available here!

 

[APanamaMama]

She now is not lifting her head or standing. Her pupils are huge - not changing with light shining in them.

 

[Goosebaby]

I’m sorry for your losses!

The chicken with the eye issues sounds like she may have just gone blind, so possibly there’s some sort of Encephalits like sickness in the flock.

What kind of wormer did you use and what dosage?
What feed are your birds eating?
Have you noticed any unusual droppings, undigested food, watery, intense green, black, red, or white?
Have you noticed any other symptoms, runny noses, coughing?

 

[APanamaMama]

The guy told me to put half a packet of ivermectin (which he gave me) in their feed for about 25 chickens. They eat growth feed. Mostly their droppings are black. No other symptoms. This comes on and kills within about four hours - only three naked necks so far have died. The others are running around normal.