DIGESTIVE SYSTEM 143 



The lymph . escapes from the blood capillaries' in the subserosa on 

 to the surface, of the peritoneum. The usual causes are obstructed 

 portal circulation, which may be due to disturbances of the liver, 

 valvular defects of the heart, chronic nephritis, or direct pressure 

 upon the portal vein. 



Lesions. — Enlarged abdomen, due to the accumulated fluid in the 

 peritoneal cavity. The fluid is thin, limpid, and is noncoagulable. 

 The lesions of the primary cause may also be observed, 



Symptoms. — A pendulous abdomen associated with digestive dis- 

 turbances and malnutrition are the principal evidences of this dis- 

 ease. 



Treatment. — Treatment is of little value. Temporary relief may 

 be obtained by paracentesis abdominis. 



PERITONITIS 



Inflammation of the peritoneum is not of as common occurrence in 

 swine as it is in horses, and the disease is less fatal in swine than it 

 is in most other animals. 



Etiology. — The peritoneum of the pigs is very resistant to infection. 

 Foreign bodies frequently become imbedded in the peritoneum and 

 establish a general inflammatory disturbance. Cesarean section, 

 spaying of sows, and the castration of ridgling boars is in some cases 

 succeeded by infection and fatal peritonitis. Parturition and par- 

 ticularly dystocia casds are prone to develop peritonitis. Septic 

 metritis is sometimes associated with peritonitis as a result of ex- 

 tension of infection. Occasionally an ascarid may perforate the in- 

 testine and produce sufficient irritation to produce inflammation of 

 the peritoneum. 



Lesions. — Peritonitis may be serous, fibrinous, hemorrhagic, puru- 

 lent, septic, or tubercular; local or general; acute or chronic. The 

 lesions will vary according to the type of inflammation. There is 

 flrst tumefaction, congestion, loss of gloss of surface, and exudation. 

 The serous exudate is sticky, serum-like, and may be tinged with 

 blood; the fibrinous exudate coagulates and causes adhesions; the 

 hemorrhagic exudate is of a bloody appearance; and the purulent 

 exudate is composed of pus. Septic peritonitis is associated with 

 the accumulation of a putrid material upon the peritoneal surface. 

 There may also be evidence of injury, or metritis, and probably 

 some intestinal content in the peritoneal cavity. Chronic peritonitis 



