In ruminants, omnivora, and carnivora, less often in horse, 1 to 1000,
or more, biliary sand to marble or more, casts; nucleus, bile pigment,
blood mucus, etc., with concentric layers of cholesterine, pigment,
salts and lime. Causes: idleness, overfeeding, dry feeding, thickening
of bile, colloids, bacteria, wintering in stable. Colloids induce
globular deposits. Parasites. Inflamed biliary epithelium secretes
excess of cholesterine and lime. Age. Acid bile, constipation.
Diseased liver. Lack of bile salts. In _solipeds_: all sizes and
numbers, green, brown, yellow or white. Liver disease. Symptoms: colic
with depression, prostration, yellow or red urine, icterus, sudden
recovery. Treatment: sulphate of soda, olive oil, antispasmodics, warm
drinks, fomentations, salicylate of soda, chloroform, pasture, or
succulent food, and open air exercise. In _cattle_: musk odor; calculi
dark green, yellowish green, whitish or orange, dry red, all sizes and
numbers. Causes: dry winter feeding, etc. Lesions: dilated biliary
ducts and bladder. 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; concretions and casts common in
distomatosis. Hypertrophied ducts. Symptoms of distomatosis.
Treatment: for distomatosis and calculi. In _swine_: rare: circular.
In _carnivora_: round, dark green, pin’s head to hazel nut. Symptoms:
colics, constipation, emesis, icterus, tender right hypochondrium,
concurrent catarrh of bowels, heart disease, dyspnœa, 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 concretions 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 not necessarily made up of smaller globular masses.
On section a calculus shows a nucleus, composed of bile pigment, 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 containing also bile coloring
matter, bile salts, and lime, in short all the constituents of bile.
_Causes._ Various conditions contribute to the precipitation of biliary
solids in the form of calculi or encrustations. The most prominent
causes are: lack of exercise, overfeeding, dry feeding, concentration of
the bile, the presence of colloids and bacterian infection.
_Idleness_ is especially operative in cattle, which are quite subject to
biliary calculi and concretions, when shut up in the stall on _abundant,
dry feeding_ for a long winter. They are not noticed in stalled animals,
that are fed watery or succulent rations, such as green fodder,
distiller’s or brewer’s swill, ensilage, brewer’s grains, mashes, roots,
potatoes, apples, pumpkins, and in case a tendency to their formation is
developed on the dry feeding of winter, the concretions may be
re-dissolved and entirely removed by the succulent spring grass. A
similar influence is noticed in the human family, as the female sex
living mostly indoors, and males pursuing sedentary occupations furnish
the greatest number of gall stones.
_Concentration of bile_ results in part from muscular inactivity and
hepatic torpor, but also from overfeeding which loads the portal blood
and indirectly the bile with an excess of solids, and from dry feeding
which lessening the secretion of water leaves the bile more dense and
predisposed to precipitate its solids. The density of the liquid,
however, developed from a rich and dry ration and a prolonged
inactivity, may continue for a length of time, without the occurrence of
actual precipitation. It usually requires some additional factor to make
this predisposition a direct cause.
=Presence of Colloids.= This may be found in the presence of solid or
semi-solid particles. Just as the introduction of a thread into a
concentrated solution of sugar or salt will induce an instant
crystallization on the filament so the presence of solid bodies
determines a similar condensation in solid form of the solids of the
bile. But this tendency is increased materially if the solid body is
itself of a colloid or non-crystallizable material. Rainey and Ord have
shown experimentally that colloid bodies like mucus, albumen, pus,
blood, epithelial cells, not only determine the precipitation of
crystallizable salts from a strong solution, but that they cause the
precipitate to assume the form of globular or spherical particles, which
by gradual accretions on their surfaces tend to grow into calculi. They
found that salts which are deposited by mere chemical reaction, without
the intervention of colloids, appear in the form of sharply defined
angular crystals. The very fact that a precipitate assumes a spherical
form suggests the presence of colloids as an active factor in the
precipitation. Heat appears to intensify this action, though probably
the normal body temperature operates mainly through the more active
proliferation of bacteria.
_Bacteridian infection._ In connection with the action of colloids it
has been observed that when such bodies are in a condition of
fermentation they are much more potent as precipitants than if inactive
and sterile. But as all fermentations are the work of microörganisms we
are at once brought to the conclusion that bacterial infection is one of
the most potent causes of calculous formations. The invading microbes
operate upon the dissolved solids, causing changes in their condition
which reduce their solubility, and thus determine the separation of
calculi and concretions in a manner allied to the precipitation of
nitrates in the soils.
But the same microbes operate in producing the colloids which coöperate
so effectively in the formation of calculi. The catarrhal biliary ducts,
or bladder, shed their epithelium, and transude white and red globules,
and form pus and an excess of mucus, all tending to the separation of
the biliary solids or forming nuclei on which these solids may condense.
The calculi and concretions tend in their turn to maintain and advance
the inflammation.
The access of the microbes to the biliary duct or bladder may be
effected through the blood of the portal vein or hepatic artery, or in
the new-born, through the umbilical vein from an infected navel. As
other modes of access may be named, a gradual advance from the duodenum
through the common bile duct, or more speedily on or in the bodies of
parasites (ascaris, strongylus, stephanurus, tænia, echinococcus,
distoma, fasciola, coccidia), etc.
_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.