62 DISEASES OF THE PLEURA 



As predisposing factors may be mentioned refrigeration 

 (cold), overexertion, long railway transports, and acute 

 diseases of the respiratory tract (laryngitis). Subacute and 

 chronic pleuritis may accompany tuberculosis, glanders, 

 contagious pleuropneumonia of the ox, tumors (spread ,of 

 sarcoma or carcinoma via contiguity of tissue, or metas- 

 tasis, and animal parasites (echinococcus of ox, cysticercus 

 tenuicollis of sheep, sclerostomies in colts). 



Symptoms. — Depending upon whether it is acute or chronic, 

 primary or secondary, the symptoms of pleuritis will vary 

 greatly. In mild circumscribed -and in chronic pleuritis the 

 symptoms are so vague that the condition is rarely recog- 

 nized clinically. In the acute form, which is at times 

 primary, they are as follows: 



(a) First stage (congestion): The onset is sudden. The 

 patient stops eating, seems stupid, and may show pains 

 simulating mild colic. There is often a marked chill during 

 which the temperature rises rapidly to 104° to 106° F. 

 The muscles of the thorax (intercostals) tremble. The 

 pulse is frequent (70 to 80), small and hard ("serous mem- 

 brane pulse"). The respirations are accelerated (25 to 40) 

 and of the abdominal type. If the pain is great, and the 

 diaphragm not involved, the ribs may be rolled forward 

 and held, breathing being performed by the, flanks. The 

 patient may not show cough or nasal discharge. 



Percussing the thorax in this stage pains the patient 

 and causes coughing. Sometimes on palpating the inter- 

 costal spaces sensitiveness is shown, especially in the region 

 of the elbow. If the examiner's hand be laid against the 

 thorax a marked fremitus may be felt. Unless the lung is 

 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. 



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