DISEASES OF THE LIVER. 253 



Excess of bile in the blood may also depend upon exces- 

 sive secretion, which also leads to absorption. 



This occurs in hepatic congestion. 



(b) Sup])ression of the secretion of bile, or interference with 

 its metamorphosis. — This may occur in certain specific fevers 

 and general disorders ; for example, influenza and pyaemia. 



Symptoms. — The symptoms of jaundice are rarely well 

 marked in the horse. As a result of impregnation with 

 bile pigment, the tissues soon become stained yellowish; 

 the conjunctivae, skin, and the visible mucous membranes 

 more especially show the yellow staining. 



The urine becomes more deeply coloured from the pre- 

 sence of bile pigment, and the motions become drier and 

 of lighter colour, from the deficiency of bile flowing into the 

 duodenum. 



Unless jaundice follows a general or specific disease, there 

 are usually no febrile manifestations, and the pulse is in 

 most instances not accelerated, and the temperature similarly 

 remains normal. 



In some cases loss of appetite and digestive disturbance 

 are marked features, and depression, languor, and incapacity 

 for exertion follow. 



Itching and cutaneous eruptions on the skin are occasion- 

 ally met with in severe cases. 



Lameness in the ofi'-shoulder is in some instances an accom- 

 paniment of jaundice. 



Tests for Bile Pigment and Bile Acids : — 



Gmelin's test for bile lyigment in the urine. — Add a drop or 

 two of strong nitric acid to a small quantity of urine on a 

 piece of white porcelain, when, if there is bile pigment pre- 

 sent, there will be a play of colours, passing through green, 

 blue, violet, and red, into a dirty yellow. 



Pettenkofer' s test fur bile acids in the urine. — Add to a small 

 quantity of the urine, in a test tube, a very small quantity 



