When there is an out-break of contagious disease, separate the sick birds from the healthy ones and clean the feeders and drinking troughs. The litter must be removed and replaced by fresh, dry material. Young chicks must receive additional heat. Sick or dead birds should be sent to the laboratory for autopsy and diagnosis. Action must be taken immediately after the detection of the first symptoms. After an outbreak of disease there should be disinfection of hen houses. There should be removal of all litter and excrement and scraping of the floor and walls. The floor, walls and all other interior surfaces must be scrubbed with lye (caustic soda) in boiling water, using one kilogram of lye to 100 liters of water. Let the equipment dry in the sun and allow the hen house to dry completely before installing a new batch of chickens. The highest layers of earth floors should be removed and a new layer of sand brought in. The main carriers are the surviving birds, which should be eliminated.