Microhic Diseases Individually Considered. 171 



black. The appetite soon disappears ; an abundaut 

 diarrhoea ensues with expulsion of a glairy material 

 and occasionally a viscid liquid may be rejected by 

 the beak. Death supervenes in a few days, some- 

 times preceded by convulsive movements; but the 

 disease may be fulminating, and we then find fowls 

 dead in their nests, the disease having produced its 

 effects during the deposition of the egg. Cholera 

 may also be of considerable duration and give rise to a 

 slow emaciation of the affected animals ; in these cases, 

 again, death is the usual termination of the disease. 



Fowl cholera is the cause of serious losses, hun- 

 dreds of poultry sometimes dying in the same yard 

 within a few weeks. The disease appears to have 

 not always the same degree of malignity ; this pe- 

 culiarity is accounted for by the great mutability of 

 the germ which occasions it. 



The changes found at the autopsy are quite con- 

 stant: the blood is dark, usually tarry in aj^pearance; 

 however, it is not uncommon to find consistent clots in 

 the cavities of the heart. The liver is large, dark, or 

 sometimes of a rather light-brown color, and dotted 

 with hemorrhagic patches; the intestines contain a 

 quivering jelly-like mucus more or less adherent to 

 the mucosa; the latter is inflamed, sometimes ulcer- 

 ated, its alterations being more marked as the disease 

 has been of longer duration ; in acute cases we es- 

 pecially notice in this situation the presence of nu- 

 merous petechise. The heart shows a characteristic 

 lesion : its external surface is dotted with hemorrhagic 

 points localized especially in the coronary groove ; the 

 pericardial sac contains a quantity of fluid exudate 

 and a gelatinous deposit adherent to the heart ; this 



