38 DISEASES OF DOMESTICATED BIRDS 
visible from the peritoneal surface. Under such conditions the con- 
tents of the duodenum consist of a pasty mass permeated with blood 
clots. The contents of the intestines sometimes consist of a cream- 
colored pasty mass, or may be green or brownish-red in color. In 
many cases the liver is permeated with whitish punctiform areas of 
necrosis. The oral, nasal, and pharyngeal cavities frequently con- 
tain a viscid mucous fluid. 
The lungs may show congestion and catarrhal or hemorrhagic 
pneumonia. More rarely caseous foci are present. Sero-fibrinous 
exudate may occur in the air sacs. 
Hemorrhages are usually 
restricted to the heart and 
duodenum, and occur else- 
where in the intestines 
rarely. Still less frequent- 
ly are they observed to be 
abundant throughout the 
® skeletal muscles. 
Microscopic examination 
of stained smears from 
heart blood and organs will 
reveal numerous bipolar 
staining rods. 
Differential diagnosis. 
Avian plague can be dif- 
ferentiated by the fact that 
no organisms are present in 
a , EGG sina from blood of a pigeon the blood as demonstrated 
it : . 
infected wi owl cholern. a, red blood by cultures or by the mi- 
cells; b, fowl cholera bacteria. (Klee) : 
croscopic examination of 
smears. Further, inoculation of pigeons and rabbits with ma- 
bee from a case of plague will not produce infection in these ani- 
mals. 
Fowl cholera has features in common with fowl typhoid. How- 
ever, diarrhea is not usual in the latter and at autopsy the intes- 
tines are found to be pale, and the contents are normal in con- 
sistency. In fowl typhoid the heart is pale and dotted with grayish 
points due to cell infiltration. A bacteriological examination is 
necessary for differentiating the various cholera-like septicemias. 
This is not necessary in practice for no information is available to 
