298 Veterinary Medicine. 



rating centre ; gray hepatization may follow the red, but very 

 commonly abscesses form in the centre of the lobulette, and, dis- 

 charging into the adjacent bronchia, cavities are formed. Another 

 common result is gangrene, with softening and partial liquefac- 

 tion. The gangrenous mass has a brownish, red or greenish 

 gray color and has a foul, putrid odor. 



The smaller bronchia are blocked with exudate and infiltrated 

 with leucocytes and fat globules, but the larger bronchia and 

 trachea show a swollen, infiltrated mucosa, and contain a red- 

 dish froth, and on the surface a scum varying in color according 

 to the nature of the material inhaled but usually of a greenish 

 gray. Under this the membrane may show red patches of con- 

 gestion, and erosions. 



In cases implicating the pleura there is an extensive effusion 

 of reddish or yellowish serum, and false membranes of varying 

 thickness on the pulmonic and parietal pleura and even, it may 

 be, on the pericardium as well. In this liquid are flocculi, gran- 

 ular matter, pus cells, and myriads of septic bacteria of divers 

 forms. The process of decomposition often generates gas so 

 that there is hydro-pneumothorax and an offensive smell. Gen- 

 erally diffused petechise betray the existence of septicaemia. 



Symptoms. There may be the history of a predisposition, 

 such as a hypostatic congestion from prolonged decubitus, or 

 severe operation, on a full stomach, under an anaesthetic ; or 

 there may have been the manifest accident of inhalation of in- 

 fected or silicious road dust, of irritant gases, smoke or hot air, 

 of some irritant liquid given through the nose or forcibly by the 

 mouth, or of solids in cases of impaired innervation of the throat, 

 or even of blood in operations on the nose or throat. A history 

 of coughing during drenching or swallowing is an important 

 indication. 



Another striking feature is the suddenness of the invasion and 

 progress. Catarrhal bronchitis with fibrinous pneumonia usually 

 sets in and advances gradually for days or even a week before 

 it reaches its acme : inhalation broncho-pneumonia makes a 

 sudden invasion and involves the smallest bronchia and the lung 

 tissue in a few hours. This is favored by the solid or liquid 

 form and the comparatively large size of the objects inhaled 

 which are thus drawn with each inspiration deeper into the 



