OBSERVATIONS AND EXPERIMENTS WITH 



NEUROLYMPHOMATOSIS 



AND THE LEUKOTIC DISEASES 



By Charles S. Gibbs, 1 Research Professor of Veterinary Science. 



Neurolymphomatosis gallinarum (Pappenheimer, Dunn and Cone, 1929) 

 or avian paralysis is a widespread, transmissible disease of fowls characterized 

 by infiltrations and tumor-like formations in the motor nerves and resulting in 

 paralysis of muscles which control motion and other functions of the body. 

 More or less related to avian paralysis is a group of diseases collectively known 

 as leukosis. 



Leukosis may be defined as a disease of the blood and blood-forming organs. 

 It is marked by changes in the blood, liver, spleen, lymph nodes, and sometimes 

 other organs and tissues. Four types of leukosis have been recognized in this 

 study: erythroleukosis, myeloleukosis, lympholeukosis, and monoleukosis. 



Patterson (1932, 1936) and Johnson (1934) consider avian paralysis and the 

 various types of leukosis to be manifestations of the same agent or virus. 

 Emmel (1935, 1936) claims that these diseases are indirectly due to infection 

 with the typhoid-paratyphoid group of microorganisms, the bacteria producing 

 hemocytoblastosis which Ultimately leads to leukosis and neurolymphomatosis. 

 Furth (1935), Gibbs (1934), and Fenstermacher (1936) present evidence to 

 show that these diseases are etiologically different, erythroleukosis and myelo- 

 leukosis being due to filterable viruses in the blood of affected birds, and 

 lympholeukosis and neurolymphomatosis being caused by proliferating cells close- 

 ly related to lymphocytes. The responsible agent in monoleukosis is unknown, 

 due to the rarity of the disease in the domestic fowl and the fact it has not been 

 extensively studied. 



ERYTHROLEUKOSIS 



Erythroleukosis is that form of leukosis in which immature erythrocytes or 

 hemoglobin-free cells appear in the blood stream. These immature erythrocytes 

 have different names according to the stage they are in when they come from the 

 bone marrow. The most common forms observed in the chicken are polychrome 

 erythrocytes and erythroblasts. The erythroblast is a more primitive form 

 than the polychrome erythrocyte, and is not always readily distinguished from 

 the myeloblast which occurs in another form of leukosis. When these primitive 

 cells are found in the blood stream in appreciable numbers, something is 

 seriously wrong either in the hematopoietic organs or in the blood itself. Simi- 

 lar types of hemocytoblastosis have been observed in extreme parasitism, 

 severe hemorrhage, toxemia, and bacteriemia. The evidence thus far indicates 

 that the appearance of immature erythrocytes in the blood is but a symptom, 

 and a satisfactory diagnosis of erythroleukosis can not very well be made unless 

 a complete history of the case is available. 



• The writer wishes to express appreciation to certain flock owners, to members of the Depart- 

 ment of Poultry Husbandry (Dr. F. A. Hays, in particular) for counsel and for birds used in these 

 experiments, and to Mr. O. S. Flint for assisting in the photographic work. Technical assistance 

 was provided for this study by the use of Educational Research Administration Funds. 



