264 Veterinary Medicine. 



to the poisoning of the nerve centres, by weakness and unsteadi- 

 ness, by complete loss of appetite, and at length an intolerable 

 fcetor of the breath as if from putrefying animal matter. In rare 

 cases recovery 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 ihe. first stage, that of congestion, the lung 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 

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

 sistency to the liver. There are gradations between congestion 

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

 retains a measure of its softness, elasticity and permeability to 

 air, though it is considerably firmer and less permeable than that 

 which is in a state of congestion, and differs further from it in 

 exuding from its cut surface not a grumous, dark bloody pulp, 

 but a clear straw colored fluid. In the advanced red hepatization 

 the lung is of a firm consistency and granular liver-like appear- 

 ance. In color it varies from a bright red to dark liver hue, 



