116 Croupous Pneumonia. 



lungs. Fibrinous or serolibrinous pericarditis is observed more 

 rarely and still more rarely acute verrucous endocarditis. 



Icterus is seen frequently in horses and is usually due 

 to a sinmltaneous gastro-intestinal catarrh or to a hemo- 

 globinemia from an influenzal or septic infection. Parencliym- 

 atous degeneration of the kidneys or acute parenclijanatous 

 nephritis are very common. They are announced l)y slight 

 albuminuria which usually disappears with the fever. Acute 

 diffuse nephritis is rare, it leads to profound albuminuria and 

 to the appearance of renal tube-casts ; renal epithelia and occa- 

 sionally also degenerated red blood corpuscles are seen. Al- 

 buminuria is of grave significance, since it points to grave infec- 

 tion which is liable to lead to degenerative changes also in other 

 organs, preferably in the heart. 



Rare complications are: acute tendovaginitis and arthritis 

 of the extremities, laminitis in the horse, iritis, acute meningitis 

 and encephalitis. In horses pneumonia is sometimes followed 

 by purpura hemorrhagica. 



Course. Croupous pneumonia is one of those diseases 

 which run a very typical course. The stages of inflammatory 

 congestion, hepatization and resolution follow each other reg- 

 ularly. In horses pneumonia usually reaches its climax toward 

 the end of the first week, i. e., on the fifth to seventh day; then 

 all morbid symptoms usually disappear rapidly within one day, 

 sometimes a little more slowly, so that the duration is at the 

 utmost two weeks in all. The period of convalescence cor- 

 responds to the intensity of the attack and usually leads to 

 complete recovery. In other animals the course of pneumonia 

 varies more or less (see page 114). 



Deviations from the normal course occur especialh' in 

 cattle and swine, although they are not rare in horses. The 

 sequence of the various stages remains the same, but the whole 

 course may be of shorter or on the contrary of longer duration. 

 Pneumonias caused by bacillus bipolaris or by external in- 

 fluences rarely take a typical course and those caused by the 

 bacillus named (in cattle, hogs and sheep) may lead, within 

 a few days, to a fatal termination. Complications which may 

 develop also produce more or less marked deviations from the 

 typical course and sometimes stand so much in the foreground 

 that the clinical picture of pneumonia becomes completely 

 clouded. 



A fatal issue in consequence of suffocation may occur in 

 very severe cases with extensive consolidation. Another cause 

 of death may be grave degeneration of the myocardium. Cases 

 with very severe infection lead to early and rapidly increasing 

 prostration ; usually toward the end of the stage of hepatization, 

 the respiration becomes much accelerated and very forced, the 

 heart is rapid and thumping, the pulse small, filiform, finally 

 imperceptible; the mucosae become livid; there is finally a 



