The story starts like this: bought 7 day-old pullets in February from a hatchery- 1RIR, 1 BO, 2 SLW and 3 EE. Grew up and did great in their brooder, then their coop, run, with access to backyard with supervision. In late July, one of my SLW started acting more lethargic, not eating, then diarrhea, more lethargy then death over about a week. Then in late August of of my EE started acting more lethargic, not eating, ruffled feathers, then died. Then last Saturday my other SLW died after the same non-specific type symptoms. She had started laying and had stopped laying a month before dying. Well now my last EE stopped laying 4 days ago, and is seeming a bit "off". Just not as vigorous as she usually is. The RIR and BO seem great. So is it weird I have lost 3 of my birds over the last 4 months? 3 days ago I treated the 3 birds I have left for lice, even though I have never seen any. I also ordered wormer (Wacine) and will treat when it comes. What else can I do/try? I am at such a loss. Are they getting it from each other? I have never had 2 birds sick at the same time. They eat Country Side organic soy-free layer feed, oyster shell and grit free choice. I give them treats like BOSS, sunflower seeds, and scratch, grapes, broccoli, melon, yogurt. They are on a dirt floor in their coop with mulch on top. I use some pine shavings in their roost and clean out everyday and wash with a mild bleach solution. I add ACV to their water. DE and peat moss for dirt bathes. Thank you so much to anyone who has read this and can give some of their insights.