So I am super new to keeping chickens, as my fiance brought home 4 pullets (14-16 weeks old not laying yet, 2 barred rock and 2 rhode island reds) that he found a farmer selling on a country road in a giant dog crate with 15 other pullets. We built a makeshift coop with a run in the back yard for them, and feed them a mixture of egg layer scratch, cracked corn, mealworms, treats, and oyster shells. One barred rock was mysteriously found dead the second day of having the chickens, with no odd droppings or symptoms at all. Then, the second barred rock started sneezing and being lethargic, and we ended up culling her as to not harm the other chickens. One of the Rhode Island Reds was sitting down alot yesterday morning so we separated her, and she was dead by evening. My fiance was so heartbroken he went out and bought 2 laying hens of about a year old from craigslist(a sex linked chicken and an arucana) and now the fourth and final pullet is being lethargic, and I am scared since he did not isolate the 2 laying hens that they are all doomed. I also know that if they do all die he will run out and buy more and I want to make sure whatever they have isn't still around when he does! The only real symptoms are lethargy and death; and sneezing/watery eyes kind of appeared in one. Please help!