146 THEORY AND PRACTICE 



The phenomena of the Hver diseases are as follows: 



1. Jaundice or icterus. This is a general 



yellowness of all parts of the body. 

 It shows in the visible mucous mem- 

 branes and in the skin, i. e., in the hu- 

 man. 



2. Lameness — in very serious acute dis- 



eases of the liver the horse oftentimes 

 is lame in his right forward quarter, 

 Occasionally he has colicky pains. 



3. Bilious diarrhoea, if the liver is work- 



ing excessively. 



4. Feces gray, in case of torpidity of the 



liver. 



5. General listlessness. 



6. Diarrhoea. 



CONGESTION OF THE LIVER. 



We recognize three congestions of the liver : 



1. Active congestion, involving the hepatic 



arterial system, — the nutrient system. 



2. Passive congestion, involving the venous 



or portal system. 



3. Biliary congestion. 



Bear in mind that there are two distinct circulations in the 

 liver, the arterial and the portal or biliary. 



In the hepatic arterial system we find that there is an in- 

 creased flow of blood to the normal liver during the active stage 

 of digestion. This is normal of course, but in disease there is 

 an excess of blood at other times than that of digestion. 



Etiology of Active Congestion.— Ovev-ietdrng on nitrogenous 

 food is a principle cause. This makes an animal plethoric. This 

 alone without any exciting cause is liable to develop hepatic ar- 

 terial congestion at any time. Exercise, especially when an ani- 

 mal is in a gross condition during hot weather excites a condition 

 of congestion. It is seen in horses that are pampered and very 

 liberally fed and more or less idle. Over-feeding with too little 



