A SURVEY AND STUDY OF SPONTANEOUS NEO- 

 PLASTIC DISEASES IN CHICKENS 



By Carl Olson, Jr.,' Research Professor, and K. L. BuUis, Assistant Research 

 Professor of Veterinary Science 



CONTENTS 



Page 



Introduction 2 



Source of material and methods 3 



Descriptions of specific forms of neoplasia 



observed 5 



Lymphocytoma 5 



Myelocytoma . . . \ 18 



Fowl leukosis 20 



Fibroma 21 



Myxoma 22 



Fibrosarcoma 23 



Osteochondrosarcoma 24 



Fibrochondrosarcoma 24 



Histiocytic sarcoma .24 



Neurogenic sarcoma .25 



Epithelioblastoma .27 



Hepatoma. . .50 



Cholangioma 30 



Thymoma . . 31 



Page 



Hemangioma 32 



Lymphangioma 34 



Leiomyoma 34 



Rhabdomyoma. 36 



Mesothelioma. . . 37 



Melanoma 38 



Embryonal nephroma 38 



Carcinosarcoma 30 



Teratoma 42 



Discussion 43 



Incidence 4.5 



Distribution of lesions 4") 



Correlation between tentative and final 



diagnoses 49 



Concomitant tumors 54 



Summary and conclusions 55 



References 55 



INTRODUCTION 



Neoplastic diseases among animals take their greatest toll from the domestic 

 chicken, where they represent a serious economic problem. This fact has led 

 to the development of many research programs seeking a solution to the prob- 

 lem. A number of types of neoplasia may occur in the chicken, although it is 

 generally recognized that those involving the cells of the hmphoid system are 

 the more common and, therefore, the more serious to the poultry industry. Such 

 recognition, however, tends to overemphasize the importance of the hmphoid 

 type of tumor and to minimize the significance of the other tumors. Even though 

 the other types are relatively infrequent in chickens, they should not be dis- 

 regarded, because as a group they are responsible for a share of the loss. Another 

 important rea.son why all types of tumors should be considered is the problem 

 of differential diagnosis. Modern science is devoting much time and energy to 

 the study of the causes, cure, and prevention of neoplastic diseases in animals, 

 as well as in man. The study of spontaneous cases of neoplastic diseases in chickens 

 is an important phase which has perhaps suffered from lack of attention and 

 careful investigation. The usual practice of investigators has been to collect 

 and describe a group of cases dealing with a specific neoplastic disease. Such 

 data do not give information on the relative frequency of different types of tumors 

 in chickens. The reports of Schneider (29) and Curtis (3) provide some informa- 

 tion on the general incidence of neoplasia, but they lack details as to the specific 

 types of disease encountered. Eber and Malke (4) have reported on 371 cases 

 of neoplasia found in 11,903 chickens submitted to the University of Leipzig 

 for examination over a period of 32 years. In the survey made by Goss (11) on 

 six flocks of chickens totaling approximately 24,000 were 1446 tumors. The 

 majority of tumors (991) were classified as "leucotic" tumors and no attempt 

 was made to further subdivide this large group into cases of lymphocytoma, 

 leukosis, myelocytoma, etc. 



'The authors wish to acknowledge the aid of other members of the Department of Veterinary 

 Science in various phases of this study, particularly Drs. J. B. Lentz and H. Van Roekel, Mr. 

 O. S. Flint, and Miss M. K. Clarke. 



