A neighbor is moving and wants to give me his two 2 year old hens. I went by his house to see the birds today and saw that they both have white poop residue sticking to the feathers around their vents. I did not get a chance to pick them up and check them out. They stayed out of his reach. From talking to him I realize he is letting them free range and only supplementing with cracked corn, no chicken feed at all. They sleep in a dog kennel on top of a 6 inch brick hard slab of of chicken poop, dirt and hay. He also has geese and ducks that the chickens are in contact with as well as a rabbit, dogs, and cats. Could the pasty butt problem be as simple as nutritional problems, worms, or parasites. They appear healthy and active. What should I check and how can I go about integrating them into my flock of 7 week old chicks.