The Development of Highly Malignant Tumor Strains from Naturally Occurring Avian Lymphomatosis

The economic importance of lymphomatosis is attested by the huge losses that it causes in all sections where poultry are kept. Much work has been done during the last two decades on the transmission and etiology of this disease. One of the greatest handicaps in its experimental study is the apparent long and variable incubation period. Deaths from naturally occurring lymphomatosis have been noted at this laboratory at ages ranging from less than 30 days to as long as birds were kept (over 1,400 days). Numerous investigators have reported the artificial transmission of various forms of the disease. It is generally thought that erythroblastosis and granuloblastosis are easily transmitted (10), but the transmissibility of lymphomatosis remains a moot question. A review of the literature will not be made here since this field has recently been covered by Lee and his group (9), Olson (10), Johnson (6), Feldman and Olson (2), and Jungherr (7). It has long been recognized that the development of a highly virulent strain of lymphomatosis would be extremely advantageous in the experimental study of the disease. The purpose of this paper is to report experiments on the development of highly virulent tumor strains from cases of naturally occurring lymphomatosis.