ICTERUS: JAUNDICE. 



277 



or septic diseases, septicemia, contagious pneumonia of the horse, 

 typhoid fever, anthrax, etc. 



Catarrhal icterus is the only one which can be looked upon as a 

 special disease; the bilious poison constitutes its principal phe- 

 nomenon. In the other two the icteric symptom is a secondary 

 matter, and may even be wanting. 



Etiolog'y of catarrhal icterus. Catarrhal icterus, which is 

 rare in the horse, is especially frequent in the dog. It most cases 

 it is but a complication of the duodenal or gastro-duodenal catarrh, 

 determined by the inflammatory obstruction of the ductus chole- 

 dochus : the bile, not being able to escape any longer into the intes- 

 tine, penetrates into the lymphatic system of the liver, and thence 

 passes into the blood. 



The causes of catarrhal icterus are confounded with those of 

 gastro-duodenal catarrh. The most common are : the irregularities 

 of meals, overloading of the stomach, ingestion of tainted food, and 

 irritations of a mechanical nature, thermies or chemicals, infections 

 of the mucous membrane of the small intestine, and blood stagna- 

 tion consecutive to heart disease. 



Anatomical alterations. The so-called catarrhal alterations 

 are circumscribed to the intestinal portion of the ductus choledochus, 

 and more especially marked toward its entrance, which is often ob- 

 structed by the inflammatory swelling. The biliary canals are very 

 much dilated (in the dog they may present the volume of a finger) ; 

 the gall-bladder is much distended by the bile, and is only emptied 

 with difficulty through pressure ; sometimes the thickened bile forms 

 a grumous, friable mass ; the finest hepatic canaliculi are the seat of 

 a bilious injection, which is clearly defined, and the ductus chole- 

 dochus may be obliterated by an exudate for a considerable part of 

 its length. The liver is voluminous, much impregnated with bile, 

 and anemic ; the hepatic cells are pigmented or atrophied (cirrhosis), 

 according to the more or less extended duration of the disease. 



All organs, with the exception of the cartilages, the peripheral 

 nerves, the white substance of the brain, the spinal cord, and the 

 horny tissue, are more or less colored yellow. 



The cadaver is anemic. The number of white globules is increased ; 

 the volume of the red globules is very variable (Siedamgrotzky). 

 We find constantly a fatty degeneration of the myocardium, the 

 kidneys are anemic, the epithelium of the eanalicula urinifera is the 

 seat of a fatty degeneration with yellowish-brown pigmentary granu- 



