132 DISEASES OF THE- BESPIRATOBY ORGANS. 



a rule, if the pus is not removed at the proper time by surgical 

 interference, it breaks out, either through the pleura into the lungs 

 and then through the bronchia, or it forms abscess somewhere in 

 the cavity of the chest, geaerally in the region of the sternum, by 

 undermining the pleura and muscles of the walls of the chest. 



Clinical Symptoms. In the primary form of pleuritis, when 

 its origin is from cold, etc., it is ushered in with more or less fever 

 and increase of temperature, the pulse increases in frequency, and 

 at the onset the animal generally has a chill; the temperature 

 remains high, and the pulse small, weak, and thready. Primary 

 pleuritis with purulent or putrid effusions is rare, and when it does 

 occur it is always accompanied with a high intermittent fever. 



The general health is very much disturbed. They are stifE and 

 sore in moving about; little or no appetite, but intense thirst. 

 The visible mucous membranes are reddened and congested, and 

 in cases where there is much exudation the membranes are dark 

 bluish-red. The feces are dry and hard. The urine presents 

 some symptoms that are diagnostic : While the exudate is forming 

 and collecting the urine is scanty and thick, and albuminous in 

 reaction. When the exudate is commencing to be reabsorbed the 

 urine increases very much in quantity, and is very clear and white 

 (see chapter on Examination of the Urine). 



There is also a marked dyspnoea. In dry pleuritis the respira- 

 tion is superficial and rapid, and where there is great exudation the 

 respirations are short and painful and the animal has all the symp- 

 toms of smothering. A characteristic symptom is the way the 

 animal endeavors to assist respiration by assuming a sitting posi- 

 tion, with the front legs spread out as far apart as possible, and 

 using the abdominal muscles, and shows pain on pressure of the 

 abdominal muscles of the affected side. The animal has a dull 

 dry, weak cough; this may, however, be absent. 



The physical symptoms are characteristic. On percussion at the 

 onset of the disease there is little change of sound, but when the 

 exudate has reached a certain height the lower parts of the chest 

 give a dull sound which seems to be limited in a straight line, 

 according to the position of the animal. Above the excretion the 

 sound is tympanitic on account of the retraction of the lung. Aus- 

 cultation gives a friction bruit in the onset, and when the fluid 

 begins to be reabsorbed and the pressure of the exudate against the 



