90 SWINE DISEASES 



substitution of leukocytes for the coagulated hemorrhagic 

 exudate that characterizes red hepatization and in part 

 to chemical change of the hemoglobin of the extra vasated 

 red blood cells in the hemorrhagic exudate. The lung 

 tissue affected with gray hepatization is gray in color, 

 dense, heavy, and cuts like liver tissue. Gray hepatiza- 

 tion persists for from three to five days, and when the 

 alveoli are relatively free of exudate and leukocytes the 

 lung is said to be in a stage of resolution, which includes 

 that period of time during which the air cells are freed of 

 all inflammatory products and return to the normal 

 condition. This is a variable period and depends upon 

 the resistance of the affected animals. The lung, during 

 this stage, contains some inflammatory products in the 

 beginning and later small quantities of mucous and 

 debris, but in the final stages the lung is practically 

 normal. 



Symptoms. Inappetence, high temperature, and 

 increased respiration and heart action characterize 

 croupous pneumonia. On the second or third day a 

 "prune-juice" nasal discharge may be observed which 

 later becomes mucous or mucopurulent. The affected 

 swine are dull, listless, and will probably cough more or 

 less when agitated. 



Treatment. Sanitary surroundings, good water to 

 drink, and an abundance of fresh air without drafts are 

 prerequisites in the treatment of pneumonia. Laxatives 

 should be given to prevent constipation. Heart stimu- 

 lants may be required, but should not be administered 

 except when necessary, as indicated by a rapid, weak 

 pulse. 



Purulent Pneumonia 



Purulent pneumonia is an inflammation of the lung 

 characterized by the formation of pus. This condition 

 is relatively common in young pigs, although it may 

 occur in swine of any age. 



Etiology. Purulent pneumonia is of bacterial origin. 

 The pyogenic Micrococci, Bacillus pyocyaneus, and 



