POULTRY DISEASES AND THEIR TREATMENT. II5 



an elevation of from i to 4 degrees of temperature. The fever 

 was of a continuous type." 



"Although the course of the disease in the different fowls was 

 usually constant, there were many variations. In a few indi- 

 viduals the time required for fatal results was from 2 to 3 weeks, 

 but ordinarily death occurred in about 8 days after feeding the 

 virus, the rise in temperature being detected about the third day 

 and external symptoms about the fifth or sixth, occasionally not 

 until a few hours before death. The symptoms observed in the 

 cases produced by feeding correspond with those described by 

 the owners of affected flocks." 



Dr. Moore found the only constant lesions to be in the blood 

 and liver. The change in the blood as noted above was a de- 

 crease in the number of white cells. The change in the liver is 

 described by Moore as follows : 



"The liver was somewhat enlarged and dark colored, except- 

 ing in a few cases in which the disease was produced by intra- 

 venous injections. A close inspection showed the surface to be 

 sprinkled with minute grayish areas. The microscopic examina- 

 tion showed the blood spaces to be distended. The hepatic cells 

 were frequently changed, so that they stained very feebly, and 

 not infrequently the cells were observed in which the liver cells 

 appeared to be dead and the intervening spaces infiltrated with 

 round cells. The changes in the hepatic tissue are presumably 

 secondary to the engorgement of the organ with blood." 



Dawson's diagnosis of the disease (An. Rep. Bur. An. Ind. 

 1898, p. 350) differs somewhat from the one given by Moore. 



It is very difficult to distinguish this disease from fowl cholera 

 except by identifying the bacteria which produce the diseases. 

 Moore contrasts the characteristic lesions in the appended col- 

 umns: 



Fowl cholera Infectious leukaemia. 



1. Duration of the disease from i. Duration of the disease from 



a few hours to several days. a few hoitrs to several days. 



2. Elevation of temperature. 2. Elevation of temperature. 



3. Diarrhea. 3. Diarrhea very rare. 



4. Intestines deeply reddened. 4. Intestines pale. 



5. Intestinal contents liquid, 5. Intestinal contents normal in 



muco-purulent, or blood consistency. 



stained. 6. Heart usually pale and dotted 



6. Heart dotted with ecchymoses. with grayish points, due to 

 ' cell infiltration. 



