We use to have a Petland in southwestern PA when I was growing up. My grandmother bought a few dogs from there at different times. One died like 2 weeks later. The others always got sick after being brought home. My boyfriend (12 years ago) got a beagle pup from there and it had the sniffles, etc. as soon as we left the store pretty much. I know of another woman who bought one from there back then and it died after like 8 days (of course they only reimburse for death for a week). They make a killing off of those pups and they all look so sad, and make you feel sad to see them penned up
I am not sure of any details about the USDA thing or mills, but I'd love to know if you find anything out!!