106 SWINE DISEASES 



tissue extending from the capsule into the purulent 

 center. Microscopically the small centers are found in 

 the beginning to be collections of leukocytes and later of 

 pus. The surrounding parenchymatous tissue will be 

 affected with cloudy swelling, as in acute parenchymatous 

 nephritis. 



Symptoms. Practically the same symptoms are 

 observed in purulent nephritis as in acute parenchymatous 

 nephritis, except that in those cases in which there is 

 absorption of quantities of pus, when there is evidence 

 of pyemia. 



Treatment. Symptomatic treatment may be of 

 value. The cause should be removed, and the patient 

 given sparingly of easily digested food. 



Chronic Nephritis 



Chronic nephritis is a common condition in swine. 

 It is not an important disease from the viewpoint of the 

 practitioner, but it is of some economic importance to 

 the packer as many kidneys are found to be affected. 

 Chronic nephritis represents a group of pathologic con- 

 ditions at least, there is a variety of different types of 

 lesions observed. One type of chronic nephritis has been 

 studied and named "chronic non-indurative nephritis," 

 but from the general lesions in these kidneys it seems 

 probable that the condition is confined to the parenchyma 

 and should be called "chronic parenchymatous neph- 

 ritis." 



Chronic Interstitial Nephritis 



Typical chronic interstitial nephritis is characterized 

 by the proliferation of fibrous tissue which may or may 

 not cicatrize. This condition includes white-spotted 

 kidneys, some large white kidneys, granular kidneys, 

 sclerotic atrophied kidneys, and all variations of the 

 foregoing. 



Etiology. Chronic nephritis, especially the type 

 involving only the supporting framework, is caused 

 primarily by relatively mild irritants acting over a long 

 period of time. These cases have not been recognized 



