150 DISEASES OF SWINE 



With regard to the disease known for years as swine plague, it 

 may be stated, in a general way, that this name as a separate dis- 

 ease has been almost entirely abandoned. It is no longer regarded 

 as a separate, distinct disease, as it has been also shown in these 

 cases that if we take the blood from an animal which is supposedly 

 suffering from swine plague and inject it into young pigs, we just 

 as often produce a disease showing all the postmortem findings of 

 the regular type of cholera as we do one one showing the lesions 

 of swine plague. 



We are, accordingly, forced to the conclusion that we have but 

 one disease to deal with — namely, hog-cholera— but that it ma^'' 

 manifest itself largely as an infection of the organs of the abdominal 

 cavity or, on the other hand, may involve principally the lungs, 

 and have more the appearance of a pneumonia. 



Typical Lung Lesions. — The typical findings of cholera in the 

 lungs do not greatly differ from those found in other parts of the 

 body. Here, as in the skin and kidneys, the lesions have a marked 

 tendency to assume a hemorrhagic form, and in such cases they 

 appear as a diffuse scattering of dark-red spots over the surface of 

 the lungs. One lung only may be affected, or both may be in- 

 volved. In many cases only a portion of the lung may be spotted. 

 In these slight lung involvements it is more common for the dorsal 

 surface of the posterior lobe to be the most markedly spotted with 

 hemorrhage. As in the skin and kidneys, these hemorrhagic spots 

 vary in size and may be very small or quite appreciably large. 

 They are usually, on an average, about the size of a pin-head and 

 rather dark-red in color. When the lung is cut into with the knife 

 it is found to be quite congested with blood, and the cut surface is 

 covered with a bloody, frothy exudate. 



This is the picture found in an uncomphcated case of cholera 

 affecting the lungs. In actual postmortem work such a picture as 

 this is rather the exception than the rule. In most cases the lung 

 involvement is quite different from this, and is much more like a 

 pneumonia than cholera. In fact, where there are marked lung 

 changes it is nearly always the rule to find with the cholera lesions 

 a compHcating pneumonia. 



In those cases which show a pneumonia the lung is firm, swol- 

 len, and has lost its elasticity. There is no longer any air in the 



