BILIARY CALCULUS: BILIARY LITHIASIS. 291 



Symptoms. In the dog and the cat we may suspect the exist- 

 ence of hepatic carciuoma when palpitation of the hepatic region 

 reveals an irregular and rough surface, or when external tumors 

 exist (especially common upon the teats). Among the morbid 

 phenomena which may accompany them we must mention : in the 

 dog, ascites (due to carcinomatous peritonitis or to cirrhosis) ; in 

 the horse, colic, also caused by peritonitis (Roll). We may observe 

 symptoms of an internal hemorrhage consecutive to softening and 

 rupture of carcinomatous tumors, which frequently contain hemor- 

 rhagic centres. 



' [Muscular emaciation is so marked and constant in this disease 

 that it may almost be given pathognomonic value ; this condition 

 is especially marked upon the masseters and temporo-maxillaris 

 muscles, giving to the patient a physiognomy that is altogether 

 special, and which may be called a cancerous cachexia. — w. l. z.] 



BILIARY CALCULUS: BILIARY LITHIASIS. 



Biliary calculi of our domestic animals but rarely give rise to 

 serious troubles (calculous colics), contrary to what is observed in 

 man — in whom, by the way, these calculi are much more frequent 

 than in animals. It is in the ox and the dog that they are mostly 

 found. They have also been found at times in the horse, the pig, 

 and the cat. 



Etiology. This morbid condition is caused by penetration of 

 alimentary particles into the biliary canals; catarrh of these canals; 

 some hepatic disease influencing the secretion of the bile ; stagna- 

 tion, condensation, decomposition of the bile, and the precipitation 

 of its soluble elements (cholesterin, calcite of bilirubin). These 

 are the principal causes capable of producing the formation of 

 biliary calculi. They may be found in the gall-bladder and in the 

 biliary canals. The smallest calculi vary in size from a poppy 

 seed to a pea ; they are generally of a round shape, oval, or cylin- 

 dric ; their surfaces are often abraded by attrition. Birbaum has 

 found as many as four hundred in one horse. The largest may be 

 ten centimetres long, and have a diameter of four centimetres; 

 those contained in the gall-bladder are pyriform ; those found in 

 the canals are cylindric ; oftentimes they considerably dilate the 

 duct containing them. 



Symptoms. Biliary calculi produce colics, which appear sud- 



