Fatigue and dark brown diarrhea, head down

[Ccort]

My 3 year old hen IS eating and drinking, but fatigued and mostly has her head down, with dark brown diarrhea.

They're not laying yet (winter) so assuming not egg bound. Should I give her Tylosin? Something else? Can the whole flock be treated with Tylosin?

 

[Wyorp Rock]

My 3 year old hen IS eating and drinking, but fatigued and mostly has her head down, with dark brown diarrhea.

They're not laying yet (winter) so assuming not egg bound. Should I give her Tylosin? Something else? Can the whole flock be treated with Tylosin?

Tylosin is used to treat infection due to respiratory illness like Mycoplasma. Does she have any respiratory symptoms?

Check her for lice/mites, make sure her crop is emptying overnight. You are in the US and the winter solstice is way in the past. Daylight hours are getting longer. This it the time of year most hens do come back into lay after a molt and break.

I'd focus on getting her hydrated. Give her some electrolytes or sugar water. See if she perks up.

I'd also consider giving her Extra Calcium for a few days to see if she's having trouble with an egg. With her being a production breed, it's very possible she's having some reproductive issues or just having a hard time coming back into lay. Hard to know.

Give 1 calcium citrate+D3 tablet once daily.

 

[Eggcessive]

You may want to add some probiotics to the food a couple of days a week. Plain Greek yogurt with live cultures can be given, about a tablespoonful to some of her food, or you could add a commercial one to feed. Probios or the generic is one your feed store may have. They also may have some others by Durvet, and here is one from Chewy:
https://www.chewy.com/equa-holistic...MI7KG6y8GxiwMVKwKtBh3bsgEhEAQYASABEgIwkvD_BwE