Mrs Farmerjen,
Im sorry to hear about your chicks, I would put my money on the issues coming from the feed lot where you bought your chicks, not the originator, ImHO I have seen some "ranch and garden" outfits that have very little knowledge about the proper care and raising of chicks, I have witnessed deplorable conditions in the chick "pen" and figured that if they dont really care just want to SELL A CHICK, then i would be careful about buying a chick or two from them, illness, lack of proper sanitation, and lack of vitamins, and nutrition is a big issue to health and wellness of chickens. I prefer buying direct from a hatchery, that way if there is a issue, they will take care of it. But a second hand bird... is a risk. in my book anyway.