Anatomical Changes. X27 



the air passages in rabbits, so tliat the clinieal picture is similar 

 to that of contagious rhinitis. Frosch & Bierbauni found a 

 specilic microorganism, the bacillus septicemia anserum exuda- 

 tivae as the cause of an epizootic purulent bronchopneumonia 

 in geese. 



Bronclioi3neunionia often occurs secondarily, especially in 

 young animals, in the course of acute infectious diseases. For 

 instance in distemper in dogs, in hemorrhagic septicemia in 

 sheep which was also known as sheep glanders, in some cases 

 of malignant catarrhal fever, in foot-and-mouth disease, in 

 sheep-pox, purpura hemorrhagica, hog cholera; more rarely 

 in chicken cholera. Tubercle and glanders bacilli, also ray- 

 fungi may ))e tiie cause of catarrhal pneumonia. (For chronic 

 catarrhal pneumonia occurring in South Africa and there called 

 "Jagziekte," or ''Hartslagziekte," see Vol. I). 



Predisposition. Predisposing' factors often play an im- 

 portant role. Such predisposing factors are : very early, or on 

 the contrary, very advanced age, cold, delnlity of the organism 

 as it occurs in anemia, in grave nutritive disturbances, in ra- 

 chitis, etc. These predisposing causes may, however, also be 

 absent in infectious catarrhal pneumonias. 



Anatomical Changes. The inflammation is, as a rule, con- 

 fined to certain foci, to individual lobules or groups of lobules ; 

 hence there are at first smaller, later on larger pneumonic areas, 

 which may become confluent and form large consolidated terri- 

 tories. These consolidated areas are usually in the neighbor- 

 hood of the lower and anterior pulmonary margin. They are 

 solid; not as firm, however, as in croupous pneumonia. The 

 cut surface is at first flesh-colored, later on more and more gray- 

 ish-red, and, when the course of the affection is very slow, yel- 

 lowish or grayish-white and then dry. The cut surface is not 

 granular; aside from catarrhal, there are also seen atelectatic 

 foci, which are a little darker, but airless, wedge-shaped, sunken 

 in under the general surface and uniformly meat-like to the 

 touch. Other portions are not uncommonly emphysematous and 

 bloated. In cattle interstitial pulmonary emphysema frequently 

 exists simultaneously. If the disease has lasted a long time 

 one may see whitish or greenish purulent foci of various sizes 

 in the consolidated areas, and in these Preisz' pseudotubercle 

 bacillus, or bacillus necrophorus, in hogs and cattle the bacillus 

 pyogenes are found occasionally. 



Swollen, partly fatty-degenerated, desquamated epitlielia, a variable number 

 of erythrocytes ami leucocytes, occasionally also threads of fibrin are seen in the 

 alveoli of the catarrhal foci under the microscope. In bronchopneumonia of cattle 

 fibrin is frequently found abundantly in the inflamed pulmonary portions. The 

 alveolar vessels are dilated, the interalveolar tissue is edematous and infiltrated with 

 round cells. 



The bronchi, especially the smaller ones, always contain an 

 abundant mucoid or purulent, occasionally more caseous exu- 



