224 Veterinary Medicine. 



Animals may recover from such pulmonary suppurations or if 

 they are too extensive the consequent depletion may induce hec- 

 tic and death. 



Gangrene of the lung is happily rare and has appeared to be 

 connected with close, foul stables, previous ill health, and work 

 after the onset of pneumonia. It is characterized by high temper- 

 ature ( io6° to io8° F. ) by great dulness and prostration due to the 

 poisoning of the nerve centres, by weakness and unsteadine,ss, by 

 complete loss of appetite, and at length an intolerable foetor of the 

 breath as if from putrefying animal matter. In rare cases re- 

 covery may take place, the dead portion having become detached 

 and expectorated. 



Consolidation from hepatization is the condition in which 

 the inflamed lung is always found, in the second stage of the dis- 

 ease. The lung has then the density and brownish red appear- 

 ance naturally belonging to the liver {red hepatization'), which 

 changes on the occurrence of softening of the exuded products to 

 a grayish hue {gray hepatization) . But after the subsidence of 

 the acute symptoms, the process of liquefaction and absorption is 

 not always complete, a portion of the exuded product becomes 

 vascular, is developed into fibrous tissue and remains permanently 

 impervious to air. Such is the state of the lung in many cases of 

 thick or short wind in horses when these have occurred as a sequel 

 of pneumonia. A horse suffering in this way has the breathing 

 habitually accelerated and is thrown into a state of great distress 

 by any attempt to make him perform hard work such as gallop- 

 ing, dragging a load up hill and the like. A chronic cough may 

 equally accompany this condition. 



Pathological Lesions. These differ according to the stage of 

 the disease. In "Ca^ first stage, that of congestion the lu-ng tissue 

 is engorged with blood as described under the head of congested 

 lungs. As early as 6 or 7 hours after artificial irritation, the 

 alveoli of the affected part are already filled by exudation and cell 

 proliferation. Until this has taken place the alveoli can still be 

 distended by blowing into the bronchial tube. 



In the second stage the condition of the lung is that of red 

 hepatisation, so called from its resemblance in color and con- 

 sistency to the liver. There are gradations between congestion 

 and red hepatisation. In the earlier stages of the latter, the lung 



