THE RESPIRATORY SYSTEM 87 



Cause. Engorgement of the lung capillaries, due to 

 overexertion, excessive heat, or disease, is the chief 

 cause of hemorrhage. Weakening of the vessel walls 

 due to malnutrition, which occurs in some infective 

 diseases, is another cause. 



Lesions. Almost all cases of hemorrhage of the 

 air passages posterior to the larynx are designated 

 hemoptysis, or pulmonary hemorrhage, and it is difficult 

 in some instances to differentiate tracheal or bronchial 

 hemorrhage from pulmonary hemorrhage. If the hemor- 

 rhage is primary the escaped and escaping blood is 

 practically all that will be observed. The blood that 

 escapes from the lung or smaller bronchial tubes will 

 contain more entangled air, that is, be more frothy than 

 that coming from the large bronchi and the trachea. 

 In secondary pulmonary hemorrhage the lesions of the 

 primary disease will also be evident. 



Symptoms. If the extravasate is limited in quantity 

 it may be absorbed and no visible symptoms become 

 evident. Escape of frothy blood from the nose and 

 mouth characterizes hemoptysis. In cases where there 

 are large quantities of blood escaping there will be more 

 or less bronchial obstruction and consequently difficult 

 breathing, and the animal may become weak from loss 

 of blood. The condition may terminate fatally or the 

 affected animal, in those cases where the hemorrhage is 

 limited, may recover. 



Treatment. Keep the affected animals cool, and 

 where they will be least excited. 



Pneumonia 



Inflammation of the lung is not of common occurrence 

 in swine as a primary condition but it is frequently 

 associated with some other disease. 



Practically all types of pneumonia based upon patho- 

 logic classification occur in swine. The following types 

 will be described: catarrhal, croupous, purulent, and 

 gangrenous. 



