Changes in the chemical composition of the bile have been invoked as a cause of gall-stones, and Naunyn has found that the inflamed biliary epithelium secretes an excess of cholesterine and salts of lime. Thomas has also observed a great increase of cholesterine in connection with a catarrhal angiocholitis in the dog.
Among other alleged causes of biliary calculi are advanced age (Rigot, Hering), acidity of the bile (Zundel), constipation, and any organic disease of the liver and bile ducts which interferes with excretion of bile.
Age is supposed to act by inactivity, lessened secretion, hepatic torpor, and the greater presumption of liver disease, acidity by the precipitation of cholesterine and the dissolving of lime present in the tissues, and constipation through hepatic inactivity, obstruction of the flow of bile, and the tendency to infection through intestinal fermentations.
It may be added that any diminution of glycocholate or taurocholate of soda or potash, decreases the solubility of cholesterine and bile acids and favors their precipitation.
GALL STONES IN SOLIPEDS.
Characters. The biliary calculi of solipeds are of all sizes and shapes. When numerous they are mostly the size of a pin’s head (Lucet). Birnbaum found in one animal 400 like peas. Dieckerhoff has repeatedly found four or five of the size of a hazelnut. Verheyen found one as large as an apple and says one exists at the Berlin Veterinary College which weighs several pounds. Rigot found 90 in the biliary ducts of an old horse, and Zundel records the death of a stallion of twenty-six years from multiple gall stones.
The calculi may be little larger than grains of coarse sand. When larger and solitary they are mostly globular or mulberry shaped; if many are together they have become polygonal by friction. In other cases notably with distomata they form hollow tubular incrustations on the bile ducts, and contain a thick grumous bile. They are usually of a green color, but may be yellowish brown, yellow, or whitish. When cut across they present a nucleus enclosed in successive layers, each successive one often differing from the last in color. Their specific gravity is low, some will even float in water when taken from the ducts, and all float when dried. Their composition is variable but chiefly cholesterine, bile acids, resin and pigments, an albumoid matter, with lime salts, etc. The nucleus may be the remains of a dead parasite, epithelial cells, blood, pus, mucus, etc. The outer layers are usually the hardest.
There may be attendant hypertrophy of the liver, cirrhosis, amyloid and other degenerations, catarrh of the biliary ducts, and distension or (according to Birnbaum) rupture of the portal vein.
Symptoms. There are no reliable diagnostic symptoms apart from the colics which accompany the obstruction of a bile duct by a passing calculus. These in the main resemble the colic of ordinary indigestion, but they may be complicated by unusual depression and nervous prostration. There may be drooping of the head, ears and eyelids, watery eyes, resting the head on the manger or pushing it against the wall. The urine is liable to be red or reddish (Jobelot), and if it or the mucosæ show a yellowish tinge it is strongly suggestive. There may be constipation or diarrhœa. The colics are severe and may last for several days (Seaman, Lucet, Burgoin) without fever and recover abruptly when the stone passes into the duodenum. They recur, however, with the impaction of another stone, and this intermittent feature, with the marked prostration, and the access of slight jaundice with each colic furnishes the best means of diagnosis.
Treatment. During the access of colic give a full dose (1 to 2 lbs.) sulphate of soda in warm water along with some active antispasmodic (belladonna, lobelia, chloroform, ether), and foment the loins and hypochondriac regions. Olive oil in large doses (1 to 2 quarts) has been found effective. Salicylate of soda in full doses is beneficial in stimulating the biliary secretion, diluting the bile, and securing some measure of antisepsis in both bowels and liver.