14 MASS. EXPP:R1MP:NT station bulletin 308 



Table 4 shows that a\ian [)aral\sis with gross lesions, or neuroI\ niijhoniatosis, 

 led all other diseases in niortalit\- and morbidity. As has been stated before, 

 three birds recovered from neuroh mphomatosis, while birds having lymphoc\to- 

 matosis and leukemia did not recover. In the last two diseases the function of 

 blood-forming organs was seriously interfered with and the birds did not live as 

 long as when affected with neurolymphomatosis. Birds suffering from chronic 

 coccidiosis, slipped tendon, ascariasis, and visceral gout lived indefiniteK' in a 

 run-down condition. According to the table, the victims of cannibalism lived 

 two da\s. At the end of this period they were either dead or on the road to 

 recovery. Birds showing complications of neurolymphomatosis and lymphc- 

 cytcmatosis lived 24 da\s, which is 15 days longer than those showing lesions 

 of uncomplicated lymphccytcmatcsis. 



This study indicates that all of these conditions are serious and should be 

 avoided as much as possible. 



The Differentiation of Neurolymphomatosis from Lymphocytomatosis and 



Leukemia 



Birds having lymphccytcmatosis and leukemia are often unable to stand, and 

 these diseases are mistaken for parahsis or neuroK mphomatosis b\- the lait\'; 

 but a trained diagnostician should observe that the comb, wattles, face, and 

 mucous membranes in cases of the former are pale, while these parts in the latter 

 are usually of good color. This observation is superficial and should not be 

 depended upon entireh- for diagnosis, yet it is of considerable help in the differ- 

 entiation of neurolymphomatosis from hmphocytomatosis and leukemia in the 

 field. The leukemias are further differentiated in that no immature red cells 

 or immature eosinophilic white cells are found in the circulating blood in either 

 neurohmphomatosis or 1\ niphoc>tomatosis, and er\throblastic and nneloblastic 

 hyperplasia are found onl\- in the respecti\e leukotic conditions. 



The examination of the blood is of the greatest assistance in the differential 

 diagnosis of poultry- diseases. Neurohmphomatosis begins with a leukoc\"tosis 

 and ends with a hmphocytosis. Differential counts indicate that the first 

 increase is in eosinophile leukoc\tes, while the last increase is in small mononu- 

 clear lymphocytes. Sometimes the leukocytosis and the hmphocytosis are found 

 overlapping, but generalh" there is a period between in which the birds apparenth' 

 hold their own for awhile and the blood count is the same as in normal fowls. 

 In other words, red blood cells, pohmorphonuclear leukocytes, neutrophiles, 

 mast cells, and monoc\tes are the same as in normal birds. In uncomplicated 

 h mphocytomatosis there is a decrease in hemoglobin, the clotting time of the 

 blood is prolonged, and the red blood cells are diminished. Leukocytosis and 

 h mphoc\tosis occur the same as in neurolymphomatosis. The remaining ele- 

 ments of the blood are seldom disturbed in this disease. 



In myeloleukosis the blood is invaded by myelocytes in various stages cf 

 development, depending upon the severity of the disease. The pathological 

 cell found in the blood and lesions of the tissues in this disease is the eosinophilic 

 myelocyte. Fig. 9. Neutrophilic and basophilic varieties of this myelocyte ma\ 

 be present in small numbers. Fresh myelocytes usually gave positive oxxdase 

 reactions when tested according to the method of Graham (1918) in the earh 

 stages of the disease. The liver and spleen were enlarged in ad\ anrcd rases, and 

 histological sections stained by Mallory's eosin and methxiene blue showed more 

 or less m\eloblastic hyperplasia. In some advanced cases the bone marrow 

 showed e\i(lence of calcification and the absence of fat. Microscopical examina- 



