Cholelithiasis. — Biliary Calculi. — Gall Stones. 537 



der, catarrh, thickening, rupture, septic peritonitis. Symptoms : relapsing 

 colic, with icterus, prostration, and tender right hypochondrium, in stalled 

 animal on dry feeding. Suggestive : not pathognomonic. Treatment : as 

 in horse : succulent spring pasturage. In sheep : rare, musky odor ;. con- 

 cretions and casts common in distomatosis. Hypertrophied ducts. Symp- 

 toms of distomatosis. Treatment : for distomatosis and calculi. In swine : 

 rare : circular. In caMivora : round, dark green, pin's head to hazel nut. 

 Symptoms : colics, constipation, emesU, icterus, tender right hypochon- 

 drium, concurrent catarrh of bowels, heart disease, dyspnoea, sudden relief. 

 Mode of relief. Treatment : olive oil, bile, sodium sulphate, or salicylate,' 

 antispasmodics, alkalies, enemata, fomentations. Laxative food, exercise, 

 open air. 



Gall stones are most frequent in animals having a gall bladder. 

 Some medical writers say they are formed in the gall bladder 

 only, but the soliped which has no gall bladder has in particular 

 instances furnished hundreds of gall stones. Yet the ox, dog, 

 sheep and pig are the common victims of biliary calculi among 

 our domestic animals. In these the calculi appear to be mostly 

 deposited from the stagnant bile in the gall bladder, yet concre- 

 tions on the biliary ducts and hollow casts inside the ducts are 

 by no means uncommon. 



A gall stone may be single, or they may be multiple up to 

 hundreds or even thousands, and when very numerous they are 

 individually small, perhaps no larger than a pin's head. They 

 may, however, attain the size of a marble or more, and by mutual 

 pressure and wear they assume various polygonal forms. If they 

 lie apart in the gall ducts or bladder they are regularly rounded. 

 They are sometimes mulberry shaped as if conglomerate. In 

 other cases the solid masses are so small as to have secured them 

 the name of biliary sand. Casts and incrustations in the ducts 

 are necessarily made up of smaller globular masses. 



On section a calculus shows a nucleus, composed of bile pig- 

 ment, blood, mucus, with the debris of parasites or bacteria. 

 Around this nucleus, the calculus is deposited in concentric layers, 

 of a hard material consisting largely of cholesterine, but contain- 

 ing also bile coloring matter, bile salts, and lime, in short all the 

 constituents of bile. 



Causes. v Various conditions contribute to the precipitation of 

 biliary solids in the form of calculi or encrustations. The most 

 prominent causes are : lack of exercise, over-feeding, dry feed- 



