THE DIGESTIVE SYSTEM 59 



Etiology. Disturbed carbohydrate metabolism is 

 inseparably associated with glycogenic infiltration, al- 

 though the specific relation of disturbed carbohydrate 

 metabolism and glycogenic infiltration is not known. 

 Inflammatory disturbances and tumor formation appear 

 to have some relationship with glycogenic infiltration. 



Lesions. A glycogenic infiltrated liver is pale, 

 larger than normal, and of a putty consistency. 



Symptoms. No definite symptoms are attributed 

 to the excessive accumulation of glycogen in the liver. 

 The condition may be suspected when the animals are 

 sluggish and do not exercise, as jt has been demonstrated 

 that during muscular activity glycogen is used in con- 

 siderable quantities and is drawn from the storehouse, 

 which is the liver, as it is required. 



Treatment. Regulation of diet and exercise is 

 far more valuable than medicinal treatment. 



Gall-stones (Cholelithiasis) 



Gall-stones are accumulations of organic or inorganic 

 substances in the various bile tubes or gall bladder. 

 They are relatively common in swine. 



Etiology. The presence of a substance that will 

 act as a nucleus is the first step in the formation of a 

 calculus. Precipitation of some of the bile ingredients 

 is the second step in calculus formation, and the accumu- 

 lation of the precipitate upon the nucleus completes 

 the process. Bits of mucous or any particle of foreign 

 matter may serve as a nucleus. Precipitation may be 

 caused by supersaturation of the bile with inorganic 

 salts, or it may be a sequel of fermentation of bile. In 

 addition,, bacteria and other factors may be causative 

 agents of calculus formation. 



Lesions. Cholelithiasis, or gall-stones, is found 

 most/ frequently in the gall bladder. It may occur, 

 however, in the hepatic duct or in any of the collecting 

 bile tubes, regardless of their size. The presence of 

 gall-stones usually causes obstruction and distention of 

 the gall bladder of the bile tubes in which they occur. 



