PNEUMONIA OK INFLAMMATION OF THE LUNGS. 141 



The causes of pneumonia, are sudden transitions from 

 heatto cold, a change from a warm stable to a colder one; 

 the most frequent is leaving the horse to stand hi a brisk 

 wind, after hard driving, or being in a free perspiration. 

 This sudden check to perspiration causes the blood to 

 recede from the surface and crowds it hurtfully on inter- 

 nal parts, producing bronchitis, pneumonia or pleurisy. 



Symptoms. — It is usually ushered in by a shivering fit, 

 the horse is cold all over, reaction after a time takes 

 place and the body becomes warmer than natural, but 

 the extremities remain intensely cold ; this condition 

 peculiarly marks the disease; it is an early symptom com- 

 mencing in its incipient or forming stage. The pulse 

 at first is often oppressed and obscure, without much 

 acceleration in its motion, The breathing is quick ; he 

 feels the need of pure air, for the air cells being more 

 or less obstructed, the atmospheric air is not brought in 

 contact with the blood, to effect in the latter that 

 change so essential to life; the animal refuses to lie down 

 because every muscle that aids in respiration is called 

 into action, and those of the spine and shoulders can 

 be used more advantageously as he stands. 



If when wearied out he lies down, it is but for a mo- 

 ment. 



It may be regarded as a favorable symptom to find 

 in the morning that the horse was down during the 

 night. 



It may not be an easy matter to distinguish pneu- 

 monia from pleurisy, and in fact they are often united. 



Pleurisy is a more acutely painful disease ; auscultation 

 here would be valuable. 



In pneumonia healthy murmur is changed to a crepita- 

 ting or crackling sound, and wherever heard will indicate 

 the extent of the disease. 



As the disease advances and lympth is poured out, the 

 lung becomes hepatized or hard like liver, and over such 

 points no respiratory murmur will be heard, for no air 

 permeates such portions. By a careful comparison of res- 



