Contagious Pneumonia in the Horse. 101 



the isolated portion fills up with dark blood globules and forms a 

 sequestrum. In the inflammatory and still living parts the color 

 is lighter with, it may be, some straw colored exudate, and 

 always an active leucocytosis, as in other inflamed parts. When 

 infiltration is located near the root of the lung, it is usually at- 

 tached to the primary bronchi, or larger bronchia and may extend 

 into the upper portion or almost the entire substance of the lung. 



Simple abscess is rare, yet purulent sacs containing the gangre- 

 nous masses or sequestra are common. 



Pleuritic areas are common over the congested and hepatized 

 foci, yet as these are usually circumscribed in extent, an exces- 

 sive hydrothorax is exceptional. Yet the pleuritic effusion may 

 at times become abundant. Friedberger and Frohner say seven 

 gallons or more. It may become purulent or even septic, exhal- 

 ing an offensive odor. Adhesions and fringes on the pleura are 

 frequent. 



The heart and pericardium may be affected, the first showing 

 the pallid, soft, or parboiled appearance of high fever, with at 

 times fatty degeneration or petechias, and the latter congestion, 

 exudation, thickening, false membranes and liquid effusion. 



The enlargement of the congested liver is a marked feature. It 

 frequently attains the weight of 30 pounds. It may ooze dark 

 blood freely from the cut surface, has usually a yellowish tinge, 

 and shows points of fatty degeneration or even of commencing 

 necrosis. The spleen is like the liver, charged with blood, and 

 shows an increase of pulp and even petechias or circumscribed 

 haemorrhages. 



The kidneys are congested, friable and petechiated. 



The bronchial lymph glands and less constantly the mediastinal 

 and abdominal ones, are congested, pink to dark red and some- 

 what enlarged. 



The gastric and intestinal mucosa may be congested, thickened, 

 haemorrhagic or ulcerated. 



The white tissues generally tend to an icteric hue, and the 

 muscles assume a mahogany aspect. 



Incubation appears to be longer than in equine influenza, vary- 

 ing in different cases from 3 to 10 days. 



Symptoms. These vary greatly in different cases, mild and 

 severe. Some, in the same stable with the severe cases, simply 



