SIMPLE PNEUMONIA IN THE HORSE. 1 7/ 



evening oscillations, then on the fifth to seventh day suddenly and 

 rapidly falls. The temperature often diminishes two to three degrees in 

 forty-eight hours. In exceptional cases it falls below normal, but soon 

 returns to that point. 



Convalescence is short. Animals can generally return to work at 

 the end of a fortnight. 



Such is the regular course of simple pneumonia. It falls naturally 

 into three periods — invasion, hepatisation, and resolution, which 

 succeed one another at almost fixed intervals. Provided the patient is 

 kept quiet and under good hygienic conditions from the outset, the 

 disease almost always assumes this regular form, independently of 

 treatment. 



In certain cases pneumonia does not pass through all the above 

 stages. It may become arrested, and resolution occur before the period 

 of hepatisation is arrived at. Under such circumstances recovery 

 is exceptionally rapid. This variety has been termed ephemeral or 

 abortive pneumonia. You saw a case in one of our patients ; moist 

 crepitation persisted in the lower part of the left lung for two days,, 

 and was then suddenly replaced by the vesicular murmur. 



In some cases complications occur. Diffuse pulmonary congestion,, 

 oedema of the lung, or myocarditis may produce asphyxia and death. 

 Endocarditis, pleurisy, synovitis, arthritis, and para- or meta-pneu- 

 monic localisations are rarer than in contagious pneumonia. 



Suppuration in the hepatised parenchyma is undoubtedly due to 

 secondary infection by streptococci or staphylococci, and forms a very 

 rare complication. M. Trasbot has only seen seven cases in a total of 

 i68 personal observations. It is marked by sudden aggravation of 

 symptoms ; the fever increases, the skin becomes hot and dry, or from 

 time to time moistened with sweat. Signs of excitement may occur, 

 but most frequently the patient is profoundly depressed. Appetite is 

 completely lost ; thirst is marked ; the heart's action becomes strong 

 and rapid, the pulse more and more feeble, the respiration very rapid, 

 short, and tremulous. On auscultation a gurgling or amphoric sound 

 can be heard; on percussion a " hniit de pot fclc " (cracked-pot sound). 

 In addition, there is often a purulent greyish or sanguinolent dis- 

 charge. When the abscess breaks into a bronchus its contents may 

 be discharged through the trachea, and recovery is possible. But 

 usually the hepatised portions of lung become infiltrated with pus, or 

 purulent pleurisy develops and the animal succumbs. 



Pulmonary gangrene is scarcely commoner than abscess formation. 



M 



