GENERAL PART OF EXAMINATION. 61 



in the blood, but in the Hver. If this organ is able to convert 

 all of the coloring matter to bile and excrete it through the 

 bile ducts, the urine will contain no bile, but the feces will 

 become stained by it (hypcrcholia) and assume a dark color. 

 It may happen, however, that the bile becomes so thick that 

 it congests the smaller bile ducts, is reabsorbed and stains the 

 urine. 



Hematogenous icterus is seen in influenza of the horse, 

 azoturia, pyemia, septicemia [Texas fever], and in certain 

 cases of poisoning, especially after prolonged chloroform nar- 

 cosis. 



2. Hepatogenous icterus is due to the free flow of bile 

 from the liver becoming retarded (biliary stasis) and its pass- 

 ing over into the blood (cholemia) via lymph vessels and tho- 

 racic duct. The obstruction may haye its seat in the biliary 

 capillaries or larger ducts, and often at the ductus choledochus 

 in the bowel. Hepatogenous icterus is characterized by the 

 appearance of bile pigments in the urine while the feces, con- 

 taining less than normal, are of too light a color. 



Hepatogenous icterus is seen in duodenal catarrhs with 

 swelling and mucous obstruction of the ductus choledochus, 

 tumors, parasites (ascarides) and concretions which block 

 the bile flow. In lupinosis and phosphorous poisoning a swell- 

 ing of the ducts and parenchyma of the liver occurs leading to 

 the collection and absorption of bile. 



Malignant icterus {icterus graz'is) has associated with it 

 mental depression and slow heart's action due to the effect of 

 the cholic and other acids contained in bile. 



III. Swelling. Swellings of the conjunctiva usually 

 are diffuse and may occur in both eyes. They are due to a 

 serous infiltration of the mucosa and submucosa. If of an 

 inflammatory character they are hot and painful. This con- 

 dition finds its best development in influenza of the horse, 

 the greatly swollen, glassy mucous membrane protruding from 

 between the half-closed lids. It is seen further in contagious 



