54 DISEASES OF THE LUNGS 



is not always present, especially in continuously stabled 

 horses. In some cases, during the stage of red hepatization, 

 a rusty brown ("prune juice") discharge occurs which may 

 last only twenty-four to forty-eight hours. In the stage of 

 resolution a yellow-colored discharge may appear. The 

 pulse at first is not much affected, but as the disease pro- 

 gresses, due to cloudy swelling of the heart, its frequency 

 is increased to 60 to 80 or higher. Quite often the pulse 

 remains high after the fever has gone down. The respira- 

 tions are accelerated early and the patient breathes with 

 distended nostrils. The conjunctiva in severe cases often 

 assumes a spotted mahogany color. The percussion varies 

 with the stage of the disease. In the earliest stage (con- 

 gestion) there is little appreciable change (somewhat tympa- 

 nitic);' in the second stage (hepatization) a flat sound is 

 emitted. The sound begins about the second day and is 

 retained three to five day. During the third stage (resolu- 

 tion) the sound becomes tympanitic again. The area of 

 dulness is usually confined to the ventral portion of one lung, 

 its dorsal limits often describing an upward curved line. 

 Auscultation: In the first stage crepitant rales at inspiration 

 — ^fine crackling sounds like rubbing hair between the fingers. 

 These sounds are usually present for the first twenty-four to 

 forty-eight hours, then pass away. In the second stage the 

 vesicular murmur is gone and there is either no respiratory 

 sound audible or tubular breathing (bronchial) is heard. In 

 the third stage moist rales are heard (the return rale). 

 General condition: Varies greatly with the case. In mild 

 attacks the appetite may be retained and the mind little 

 perturbed. In severe cases there is no appetite while the 

 fever is on, and the animal is very stupid and languid. 

 Horses usually do not lie down until the fever drops. Small 

 animals and even ponies lie down most of the time during the 

 disease, and if only one lung is affected, on the diseased side. 

 The urine is scanty and high colored until the fall of the 

 fever when its specific gravity drops and the quantity, voided 

 frequently, greatly increases. 



' The flat percussion sound may not be obtained, if the pneumonia involves 

 the central rather than the peripheral portion of the lungs (pneumonia 

 centralis) . 



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