CATARRHAL JAUNDICE. 91 



tion of the mucous membranes extends to the duodenum, and the 

 ductus choledochus becomes closed by the swelling of its mucous 

 membranes and prevents the exit of bile. As soon as such an 

 obstruction occurs the bile can no longer flow into the intestines; 

 it becomes stagnant and dams back, causing a pressure in the bile- 

 ducts, and being unable to escape it finally enters the lymphatic 

 vessels of the liver, from them into the blood through the thoracic 

 duct. After this there followo a series of symptoms that have been 

 named jaundice (icterus). In the earlier stages of the disease we 

 have to deal with an icterus that is produced by stagnation of the 

 bile. Tliis has a number of names — stagnating icterus, icterus of 

 reabsorption, or hepatogenous icterus. While the swelling of the 

 mucous membranes is generally the cause of this disease, still there 

 are a number of other causes that may also produce it, such as 

 foreign bodies in the ducts (parasites, gallstones), and also from 

 ulceration of the mucous membrane, by the cicatrix of tumors, 

 abscess in or near the liver. The stoppage of the flow of bile sets 

 up an inflammation of the tissues and sometimes forms abscess of 

 the liver; but as the great majority of oases are caused by the 

 catarrhal form, we will describe that. Any cause that will produce 

 catarrh of the stomach will finally produce icterus — improper food, 

 especially when it is frozen ; cold drinks after over heating, decayed 

 meat, salt fish. That form of icterus that is often seen during 

 distemper is very likely to be catarrhal. 



Pathological Anatomy. The symptoms of catarrh of the 

 duodenum are always present; the vessels are more or less injected, 

 and the mucous membrane swollen. As a rule, the mouth of the 

 duct is closed, and it is only by very strong pressure on the gall- 

 bladder that we are able to open it and force out the bile in the 

 duct. In some cases a white clot of mucus is forced out, but 

 Siedamgrotzky has found that in the great majority of cases it is 

 due to swelling of the intestines and not to catarrh of the mucous 

 membrane of the duct. 



In some post-mortems we may not find any swelling in the 

 region of the duct, but very frequently the post-mortem changes 

 are so quick as to be hardly recognizable at the autopsy. Another 

 fact to be taken into consideration is that the canal is so very nar- 

 row in the dog that it takes a very small amount of swelling to 

 obstruct it. 



