Swine Groivers' Association. 



297 



pink color and collapse when the chest cavity is opened, and are 

 soft and pliable to the touch. In many cases of cholera the lungs 

 have a normal appearance. In other cases the lungs present a 

 wide range of disease changes, varying from a few minute hem- 

 orrhages, on one or two lobes, to an almost complete solidification 

 of both lungs. Frequently there is an extensive, straw-colored, 

 coagulated exudate covering one or both lungs. This coagulum 

 causes a slight adhesion of the lungs to the ribs; this adhesion is, 

 however, easily broken down by the fingers. In prolonged chronic 

 cases of cholera, white fibrous bands "pleuritic adhesions" are 

 sometimes found binding the lungs very firmly to the ribs. These 

 lung complications are often mistaken by farmers and by veteri- 

 narians for an ordinary pneumonia or pleurisy, and have also been 

 called "swine plague." 



Fig. 5. Diseased lung in hog cholera. The so-called "swine plague'' form. The darkened areas 

 show the parts most frequently affected. They become solid and liver-like. 



Veterinary Department, Missouri Experiment Station. 



The heart, in many cases, shows no signs of the disease. In 

 others the walls are the seat of numerous spots of hemorrhage. 

 These occur more often on the outer wall than on the inner sur- 

 face, and at the base of the heart, on the auricles, rather than on 

 the ventricles. 



In an outbreak of cholera, nearly all the diseased conditions 

 mentioned have sometimes been found in the first one or two an- 

 imals examined, and a positive diagnosis is quickly established. 

 On the other hand, the first animal examined may reveal but little 

 that is regarded as typical of the disease, and a failure to diagnose 

 the trouble may result if another hog or two are not examined. 

 It should be remembered that cholera is primarily a blood infec- 



