206 SWINE DISEASES 



ing different stages of progress of the disease, such as con- 

 gestion, red hepatization, gray hepatization, and later 

 necrosis in which the necrotic material may be liquid or 

 caseous. As a result of the variation of the progress of 

 the disease in different areas the affected lung has a 

 marbled or mottled appearance. There are some inter- 

 lobular infiltrations; the bronchial and mediastinal 

 glands may contain hemorrhages or necrotic centers; 

 the pleura is usually affected with a fibrinous pleurisy 

 with or without adhesions. In the more chronic cases 

 the necrotic foci in the lung become more numerous and 

 there may be a purulent or septic pleurisy due to the dis- 

 charge into the pleural cavity of the necrotic pulmonary 

 centers. There will be a diffuse redness of the skin. 



Swine plague is frequently associated with hog cholera, 

 and then the various lesions characterizing that disease 

 will be 'present also, all of the lesions being variously 

 modified. 



Symptoms. The period of incubation, at least in 

 artificially infected cases, is of short duration, rarely 

 exceeding two days. The septicemic type is ushered in 

 suddenly with a high temperature, though it rarely ex- 

 ceeds 105 degrees Fahrenheit, accompanied by inappe- 

 tence, weakness, and little tendency to move. The blush 

 of the skin due to hyperemia may be observed. This 

 form is rapidly fatal, the course rarely exceeding twelve 

 hours. 



The ordinary form of swine plague is evidenced by 

 the usual symptoms of pneumonia, such as short, dry, 

 spasmodic cough, dyspnea, temperature up to 105 de- 

 grees Fahrenheit, a disposition on the part of the affected 

 animals frequently to sit on their haunches like a dog, 

 mucous or mucopurulent nasal discharge, diminished 

 appetite and finally cessation of appetite, and usually 

 constipation. As the disease progresses, breathing be- 

 comes more difficult and there is extreme weakness and 

 emaciation if the affected animals live long enough. 

 The blush of the skin is usually present, and there may be 

 conjunctivitis. The acute form usually terminates fatally 



