Fowl Paralysis and Other Forms of the Avian Leukosis Complex

The disease called fowl paralysis, together with several other allied conditions classed together as the avian leukosis complex,^ causes a tremendous loss to the poultry industry. The paralysis form of this disease complex was first recognized in the United States along the eastern coast about 1920. During the last 20 years the avian leukosis complex has spread rapidly until few flocks of chickens in the United States have escaped its ravages. Its yearly toll in this country is believed to exceed that of any other poultrj^ disease and it also causes great damage in other countries of the world where the production of poultrj^ is conducted