PLEURISY 595 



INFECTIOUS PNEUMONIA 



A few years ago, during an outbreak of disease among swine 

 in northwestern Missouri and southwestern Iowa, Dr. Kinsley and 

 other veterinarians reported what they believed to be a contagious 

 form of pneumonia. This disease did not seem to have the charac- 

 teristics of either pneumonia or hog-cholera, and seemed to them 

 to be a new disease. 



Investigations made by veterinarians connected with the 

 United States Bureau of Animal Industry Station at Ames, Iowa, 

 demonstrated that the disease in question was really hog-cholera. 

 Blood from the diseased animals, taken to the station at Ames and 

 injected into healthy pigs, produced typical symptoms and post- 

 mortem findings of hog-cholera. 



From these findings we must conclude that a contagious pneu- 

 monia does not exist as a separate and distinct disease. This case 

 does illustrate, however, the frequency with which even experts 

 may be deceived as to diagnosis between pneumonia and hog- 

 cholera. 



PLEURISY 



Definition. — The pleura is the bright, shiny serous membrane 

 which lines the inner surface of the chest and is reflected over the 

 lungs. Inflammation of this membrane is known as pleurisy. It 

 is commonly seen in combination with pneumonia, and the combi- 

 nation of the two diseases is sometimes referred to under the name 

 of pleuropneumonia. 



Causes. — The causes of pleurisy do not markedly differ from 

 those of pneumonia. Poorly ventilated, drafty pens are especially 

 liable to produce inflammation of the pleura. Exposure to cold wet 

 weather is another very fruitful cause. Injuries to the chest wall 

 are perhaps the most common cause in the hog. A kick from a 

 horse or steer, or being tramped on by one of the larger animals, is 

 especially liable to produce a pleurisy. 



Pleurisy is commonly met with as a complication of such dis- 

 eases as hog-cholera and tuberculosis. The disease may be of 

 either an acute or chronic type. More commonly it is of the acute 

 type. 



Symptoms. — The disease usually starts in with a chill or a num- 

 ber of repeated light chills. The temperature rises somewhat, but 



