Comparative Studies of Strains of Pleuropneumonia-like Organisms Isolated from Cases of Chronic Respiratory Disease in Poultry
Thesis - Open Access
Master of Science (MS)
Department / School
Chronic respiratory disease in chickens and infectious sinusitis in turkeys were first recognized as clinical entities in the Unites States in 1942. They are now considered as diseases of major economic importance throughout the poultry industry. The loss from chronic respiratory disease and infectious sinusitis to the United States poultry industry has been estimated as 100 million dollars per year. Losses from mortality are less than those occurring in other respiratory diseases. The greatest loss comes through decreased growth rate and loss of egg production. The slower growth requires more time to prepare birds for market and there is a greater chance of loss from secondary infections. Work has been done on a pleuropneumonia-like organism vaccine in broilers, but without success. Serological testing has proved to be an effective means of checking for possible infection. It has been suggested that flock weeding similar to the pullorum program could be used for chronic respiratory disease and infectious sinusitis. This plan has not yet been put into effect. It fails to yield complete elimination of the disease or the agents when used on large flocks over a large area. Luginbuhl (37) stated that poultry management has played a major role in keeping poultry flocks free of the pleuropneumonia-like organisms. At the present time it has been accepted that chronic respiratory disease and infectious sinusitis are caused by one or possibly two infecting agents. The first is one of the group of pleuropneumonia-like organisms, and the second is a bacterium or virus, which is thought to be required in addition to the pleuropneumonia-like organisms to produce the severe form of chronic respiratory disease and infectious sinusitis. Luginbuhl (37) states “….ORD has been seen to be mild when infecting chickens by itself and sever when aided by secondary invaders, as bacteria or viruses”. It is also generally accepted at the present time that the agent causing chronic respiratory disease of chickens also cause infectious sinusitis of turkeys and that this agent is transmitted through the egg to the progeny from infected parents.
Library of Congress Subject Headings
poultry -- Diseases
Includes bibliographical references
Number of Pages
South Dakota State University
Brand, Orville M., "Comparative Studies of Strains of Pleuropneumonia-like Organisms Isolated from Cases of Chronic Respiratory Disease in Poultry" (1960). Electronic Theses and Dissertations. 2710.