168 Inliamniation (if the Pleura. 



capsulated exudate the horizontal boundary of the area of dull- 

 ness is absent and it does not change ^dtli the changing posi- 

 tion of the body. Tympanitic sounds are observed only in 

 those rare cases in which, with a decrease of the fluid, the su- 

 perficial layer of the erstwhile collapsed lung portions again 

 contain air. In smaller animals tympanitic sounds are hciird 

 also over those portions of the thorax which are not occupied 

 by fluid; the same condition is also observed in a lateral posi- 

 tion of such animals. The cause of the t>anpanitic sound in 

 smaller animals is furnished in a comparatively considerable 

 diminution of the sounding column of air enclosed in the thorax. 



Auscultation show^s absence of friction sounds in the area 

 of dullness; further upward they are, however, commonly 

 heard later on. The other respirator}^ sounds are likewise 

 much diminished or absent in the area of dullness, and along 

 the upper boundary indefinite or bronchial breathing is lieard 

 in many cases. If, however, the lung has become adherent at 

 the onset of the disease or previously, bronchial l)reathing is 

 heard also in the area of dullness. The vesicular breathing is 

 intensified above the area of dullness and on the healthy side. 



The apex beat is weakened on the diseased side and the 

 heart sounds are duller and weaker. Toward the termination 

 of severe cases the sjanptoms of cardiac weakness appear. 



The temperature (Figs. 27 and 28) does not give a typical 

 curve. Great variations of temperature are usually seen in 

 the later course of the disease. Remittent or continuous fever 

 in less acute cases is occasionally interrupted by fever-free in- 

 tervals. Very high fever is usually seen in purulent or ichor- 

 ous pleuritis. 



Continuous standing during the course of the disease is 

 frequently observed in horses. If the animals lie down ex- 

 ceptionally they rest on the sternum or on the healthy side, as 

 do other animals in the beginning stage of pleurisy, in order to 

 protect the tender portions of the thorax against pressure ; after 

 an exudate has been formed they lie on the diseased side, so 

 that the healthy portions of lung have a chance to expand. If 

 animals in this stage are, during examination, placed upon the 

 healthy side, the dyspnea is at once markedly increased and the 

 animals may even suffocate, because the healthy parts of the 

 lungs are compressed l)y the body weight, and the affected por- 

 tions by the exudate. 



The appetite is capricious and only becomes normal after 

 recovery has set in. If the disease lasts for a long time the 

 animals become markedly emaciated. 



The amount of urine is diminished in the beginning; the 

 amount of chloride of sodium diminishes markedly as the exu- 

 date forms, while its absorption leads to an increase of urine 

 and of its chloride of sodium contents (urinary crisis). Al- 



