172 Inflammation of the Pleura. 



Pleuritis with fluid exudate is characterized by the following 

 clinical picture : marked horizontal dullness, often on both sides, 

 strong increase of resistance and the absence of respiratory 

 sounds in the area of dullness. Exploratory puncture may be 

 necessary to clear up a doubtful case. Croupous pneumonia is 

 differentiated by the presence of an area of dullness which is 

 bounded upward by a curved line or which rises or falls pos- 

 teriorly, and by bronchial breathing which is audible at least 

 from time to time. The initial symptoms are also very different. 

 The onset of pneumonia is characterized by a reddish yellow 

 discoloration of the mucosae, eventually by a rust-colored nasal 

 discharge, by deep and difficult respiration and by a strong 

 pulse; in the beginning of pleurisy the respiration is much 

 accelerated, superficial, almost trembling ; the pulse is hard and 

 small and the hand placed on the chest wall can detect a mus- 

 cular tremor. The fever curves of the two diseases differ mate- 

 rially. The course of the fever in pleurisy is similar to that in 

 catarrhal pneumonia ; however, a continuous area of dullness 

 is either absent or it is shaped as in croupous pneumonia. 



The difficulties increase, however, when it must be decided 

 whether pneumonia and pleurisy exist simultaneously^ The 

 shape of the area of dullness is then not decisive, because 

 fluid below and infiltrated lung floating on it above may give 

 a curved boundary line of the area of dullness. One also hears 

 bronchial breathing sounds in the floating lung especially near 

 the upper boundary of the area of dullness, as it is often found 

 in croupous pneumonia. The behavior of the apex beat and 

 of the heart sounds often is decisive; a diminution in their 

 intensity points to pleurisy. Important also is the presence of 

 edema on the inferior thorax, which does not occur in pneu- 

 monia. 



The differential diagnosis between pleurisy and pleuro- 

 pneumonia in cattle may be difficult when pneumonia consoli- 

 dation exists simultaneously with pleurisy. The concomitant 

 circumstances, such as the possibility of importation of the con- 

 tagion must then be considered. A suspicion of the existence 

 of pleuropneumonia appears justified where subacute or chronic 

 pleuritis or pleuropneumonia are found and where the possi- 

 bility of a contagion cannot be excluded. 



Pleuritis may be distinguished from pericarditis by the 

 fact that in the former case the apex beat is not as much inten- 

 sified and as rhythmic as in the latter case ; the friction sounds 

 in pleuritis are usually heard on one side only, they are influ- 

 enced by the respiratory movements, and friction sounds and 

 tenderness of intercostal spaces are usually found in other areas 

 aside from that of the heart. Apex lieat and heart sounds are 

 almost absent in pericarditis with effusion; this is contrary to 

 what is found in pleurisy. 



Anamestic data and the eventual simultaneous presence 



