66 DISEASES OF THE PLEURA 



involved in this stage there is no change in the percussion 

 sound. 



The respirations seem shorter than normal and of an 

 interrupted, catching character. On auscultation a rubbing, 

 grating, frictional sound is heard synchronous with the 

 respirations. In rare instances the grating sound may be 

 heard a distance from the patient. The animal is usually 

 stiff and when turned "moves as one piece" in a rigid 

 wooden fashion. 



(b) Second stage (effusion): In this stage the clinical 

 picture is a good deal modified. The patient becomes more 

 dyspneic, and the character of the breathing changed 

 depending upon the quantity of exudate in the chest. If 

 a considerable amount of fluid forms rather rapidly in the 

 thorax (25 to 40 liters), at inspiration the ribs are rolled 

 forward ad maximum and at expiration, which is accom- 

 plished by a double-pumping movement of the flanks, the 

 lumbar region is elevated and the anus protruded, the 

 manner of performing the respirations much resembling that 

 noted in pulmonary emphysema. Along the costal carti- 

 lages at each expiration a groove is formed. The nostrils 

 are dilated and often flapping. Percussion: As high up as 

 the fluid in the chest extends, a marked flatness with resist- 

 ance under the hammer is noted. The flat area extends 

 across the ribs in a straight horizontal line. Above this 

 line subdued resonance is heard. Changing the position of 

 the body will shift the horizontal line. (Only feasible in 

 small animals.) Auscultation: When effusion occurs the 

 frictional sound disappears (in some instances it may still 

 be heard above the area of flatness), and, as a rule, no 

 respiratory sounds can be determined below the horizontal 

 line. Above it the vesicular mm-mur is harsh; tubular 

 breathing is frequently present. 



The heart beat is weakened in this stage and may often 

 be heard more distinctly on the right than on the left side 

 of the chest. The pulse is rapid and softer than in the 

 first stage. The temperature is very irregular. In sero- 

 fibrinous pleuritis, when effusion takes place, it usually 

 drops to nearly normal, but may rise again later. Its 



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