130 Catarrhal Pneumonia. 



the thorax. The fever may, however, disappear again within a short 

 time; the appetite may improve, yet the signs of pneumonic consolida- 

 tion persist without influencing the general nutrition or the yield in 

 milk. In this form the disease lasts about fourteen to eighteen days and 

 reaches its climax about the tenth day ; then the symptoms decrease and 

 most animals recover completely (Lewek). Occasionally the course may 

 be less favorable. In both forms interstitial pulmonary emphysema is 

 not infrec^uently developed. 



Course. Catarrhal pneumonia follows a very variable course, 

 in accordance with the variety of its causes. It develops very 

 rapidly in some cases and may have assumed a considerable ex- 

 tent within a few days ; the development is slower in other cases 

 and the course may extend over several weeks and even months. 

 The fever subsides in favorable cases toward the end of the sec- 

 ond or third week, or often even earlier; the cough becomes 

 easier, moist, less frequent; the respiration less accelerated and 

 forced, and complete recovery takes place. Renewed elevations 

 of temperature may come on during the period of recovery; this 

 is then due to the formation of new inflammatory foci. 



In other cases the disease takes a fatal termination, and the 

 animals die from suffocation, cardiac paralysis, exhaustion, in- 

 tercurrent pleuritis or pericarditis, or from profuse diarrhea, 

 occasionally also from pulmonary gangrene or in consequence 

 of a general sepsis. Again, in other cases there may remain a 

 chronic pulmonary induration ; the animals then suffer in their 

 nutrition and from respiratory difficulties. Young animals are 

 retarded in development under these circumstances. 



Diagnosis. The greatest difficulty is offered by the differ- 

 ential diagnosis between catarrhal pneumonia and bronchiolitis ; 

 a careful physical examination, however, often enables us to 

 come to a definite conclusion. High fever, absence of vesicular 

 breathing, and particularly dullness on percussion, speak in 

 favor of catarrhal pneumonia. Catarrh of the bronchioles 

 rarely exists for any length of time without the advent of ca- 

 tarrhal pneumonia. Croupous pneumonia can be distinguished 

 by its much more rapid development, its acute and cyclical 

 course, by the extensive and strong dullness, the bronchial 

 breathing which is frequently present over a wide territory and 

 finally by its often favorable termination. Bronchopneumonia 

 in cattle can not be differentiated from pulmonary tuberculosis 

 without any further study when it takes a someAvhat pro- 

 tracted course. In contradistinction to pulmonary tuberculosis, 

 bronchopneumonia does not lead to severe emaciation, even 

 after severe local changes, and the catarrhal sounds remain, as 

 a rule, confined to the anterior and inferior portions of the 

 thorax. 



Prognosis. The prognosis is the more unfavoral^le the 

 younger or the older the animal. The poorer the state of nutri- 



