NEUROLYMPHOMATOSIS IN CHICKENS 9 



Since Ixniphocytomatosis is more common in !a\iiig hens than it is in pullets, 

 cockerels, and roosters, it may be that concentrated feeding and forced la\ing 

 are important factors in the incidence of this disease. 



Richardson (1933) has suggested "that catarrhal enteritis with extensive des- 

 quamation of the epithelium co\'ering the villi is the primar\' lesion, with sub- 

 sequent absorption of toxins from the digestive tract, causing a hyperplasia of 

 the lymphoid tissue normally found in the various organs" may be responsible 

 for the tumors in lympholeukosis. which are similar, if not the same, as in hmpho- 

 c\tomatosis. Lymphoc>'toma of the o\ary is shown in Fig. 5. 



Chart 1 represents the incidence of neuroKmphomatosis, hmphocytomatosis, 

 and neurolymphomatosis complicated b\" hmphoc\tomatosis at various age 

 periods in the chicken, pullet, cockerel, hen, and cock. 



Neurolymphomatosis 



Uearolyrjphomatosis 

 conrplicated with 



Lymphocytomatosis 



Lymphocytoraatosis 



II II 



CHICZSIIS 20 to 120 DAYS OLD 



II II h 



PULLETS AND COCKEHELS 121 to 240 DAYS OLD 



I I I I I 



I 



Feaales hlales Females Males Pen^.a.les Males 



HENS AND COCZS 9 to 12 MONTHS OLD 



