246 MANUAL OF EQUINE MEDICINE. 



with epizootic diseases. When intiuenza is accompanied by 

 this form of congestion of the liver, it is termed bilious or 

 biliary influenza. 



Etiology. — The chief causes of the various forms of hepatic 

 congestion are, previous pulmonary or cardiac diseases, 

 specific feters, dietetic errors, chills from exposure, and 

 over-exertion of plethoric animals after a full meal. 



Symptoms. — Slight jaundice, evidenced by the yellow- 

 tinge of the conjunctivae, is usually a noticeable feature, 

 especially in the variety described as biliary congestion. 



Signs of digestive disturbance, such as loss of appetite 

 and irregular action of the bowels, are usually manifested. 

 Febrile symptoms are rarely present, unless the congestion 

 be associated with some specific fever. 



The extremities are cold, and pressure over the region of 

 the liver causes pain. 



The urine is generally scanty, and is more highly 

 coloured than normally, and not unfrequently contains bile 

 pigment. 



Morbid Anatomy. — When congested, the liver is often 

 considerably enlarged, from the great amount of blood it 

 contains. This is especially the case in passive hypersemia 

 of this organ. The term nutmeg liver is applied to the 

 peculiar variegated appearance of the surface on section 

 which is found in cases of long-standing mechanical con- 

 gestion. 



This condition is characterized by a large accumulation 

 of blood in the hepatic veins, which become dilated and 

 thickened ; by atrophy of the hepatic cells in the central 

 portions of the lobules, and by increase of the inter-lobular 

 connective-tissue. 



The impediment to the return of blood causes the atrophy 

 of the hepatic cells, and the formation of granules of pig- 

 ment. When examined microscopically, the lobules are 



