DIGESTIVE SYSTEM 105 



titles of food material in it and usually an associated condition that 

 produces the primary obstruction. 



Symptoms. — Symptomatically, the dilatation is not positively dif- 

 ferentiated antemortem from obstruction, the symptoms of both con- 

 ditions being practically identical. 



Treatment. — In cases of dilatation, remove that which primarily 

 causes an obstruction and then administer tonics to facilitate the 

 return of intestinal tonicity. 



EMPHYSEMA 



Single air cysts or clusters of air cysts are not of infrequent 

 occurrence, involving and protruding the serous coat of the intestine. 

 This condition appears to produce no inconvenience and is of no 

 particular economic importance. It has been thought to be the 

 result of bacteria, probably of the colon group, which have pene- 

 trated through the intestinal wall to the serous coat, where they pro- 

 duce fermentation and the gas evolved is accumulated beneath the 

 serous membrane. These air cysts vary in size from a pinhead to 

 a pea, and there may be only a limited number of them or myriads. 

 Occasionally they are so prevalent that the intestine will float on 

 water. 



This condition is of no practical consequence, as the flesh from 

 an animal in which this condition" occurs is not damaged and is 

 wholesome for human consumption. 



ENTERITIS 



Enteritis is inflammation of the intestine and may be catarrhal, 

 croupous, diphtheritic, mycotic; simple or infective, acute or chronic. 

 Catarrhal enteritis may be either acute or chronic. 



Acute Catarrhal Enteritis 



Acute catarrhal enteritis is a common ailment of swine. 



Etiology. — The usual cause of this disease is improper food. The 

 natural habits of swine are conducive to the introduction of various 

 microbes into their food and drink, and swine are frequently fed on 

 materials that a're partially decomposed. Their fo'od not infre- 

 quently contains chemical substances that are sufficiently irritating 

 to establish a catarrhal gastritis and enteritis. The ingestion of 

 foods of extreme temperatures may excite catarrhal enteritis; not 



