I knew that. I bought three beautiful Spanish bantams and as I talked with the owner, it seemed that they had come from a good caring home. They turned out to have respitary disease and bad scaley legs. I have been building them up for a week now with multivitimans, yoghurt, boiled eggs, bird seed....anything to build up their bodies' natural defence system. I am treating them with vetRX five times a say and have been using vaseline on their legs. The birds are beginning to eat better and have put on a little weight and their leg 'scabs' are dropping off. They still have mucus but the breathing is slowly improving. The birds are still in a far barn on their own in quarantine and I have my fingers crossed for the rest of my birds. Its not worth the risk of buying the unknown from an auction.