URO-GENITAL SYSTEM 185 



occur primarily in the kidney. Constipation is probably a predis- 

 posing factor of colon-bacillus invasion of the kidney. 



Lesions. — Suppuration may be circumscribed, thus forming an 

 abscess or multiple abscess, or it may be diffuse. Metastatic puru- 

 lent nephritis usually involves both kidneys, and small suppurative 

 centers occur as gray or yellow areas which are surrounded by a 

 hyperemic zone. The larger foci may be quite definitely circum- 

 scribed and frequently have small bands of fibrous 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 puru- 

 lent nephritis as in acute parenchymatous nephritis, except that in 

 those cases in which there is absorption of quantitis of pus, there 

 is evidence of pyemia. 



Treatment. — Symptomatic treatment may be of value. The cause 

 should be removed, and the patient given sparingly of easily di- 

 gested 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 patho- 

 logic conditions — 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 con- 

 fined to the parenchyma and should be called "chronic parenchy- 

 matous nephritis." 



Chronic Interstitial Nephritis 



Typical chronic interstitial nephritis is characterized by the pro- 

 liferation 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 



