Cattle 1853 - Lewis Family Farm

321 . CATTLE.
retiring to the fence, either slowly pace along the side of it, or stand
hour after hour, listless and half unconscious. Not only the skin,
but the very hair, gradually becomes yellow ; a scaly eruption ap-
pears, attended by extreme itching,- and sometimes degenerating into
the worst species of mange. It is seldom, indeed, that bad mange
appears among cattle without being accompanied by a yellow skin ;
and the cutaneous eruption was probably caused by the presence
and constant excretion of bile irritating the exhalent vessels of the
skin. A state of costiveness usually accompanies the yellow skin, at
least in the early period of the disease, although diarrhoea, which no
astringents will subdue, may afterwards appear, and, in fact, will
generally wind up the affair, and carry the patient off. Jaundice
cannot long exist without being accompanied by general impairment
of health and loss of condition. Cows are particularly subject to it
in spring and autumn. The milk soon shares in the j r ellowness of
the other secretions, and occasionally acquires an Hnpleasant and
bitter taste.
The usual cause of jaundice is obstruction of the passage of the
bile from the gall-bladder into the duodenum. This obstruction is
effected in various ways ; but most frequently by biliary concretions,
calculi, or gall-stones. During the continuance of the bile in the
gall-bladder, a certain portion of the water which it contains is removed
by the process of absorption ; the residue becomes proportionably
thickened, and the most solid parts are either precipitated,
or form themselves into hard masses. Biliary calculi are not unfrequently
found in the gall-bladder of cattle, of varying size, from that
of a pin's head to a large walnut. Their form indicates that they
were composed by some process of crystallization ; they are round,
with concentric circles, or conical, or assuming in a rude way the
form of a cube, or a pentagon, or hexagon. There is usually soma
central portion of harder bile round which the rest is collected. They
are of less specific gravity than the bile, and even than water, and
are found swimming in the gall-bladder. They are composed of the
yellow matter of the bile, with a portion of mucus holding it to-
gether. It is insoluble in water and alcohol, but it readily diffuses
itself in a solution of potash.
So far as can be observed, the presence of these calculi in the gallbladder
does not inconvenience the animal, or interfere with health,
for they are found in great numbers of slaughtered oxen. At all
events, there are no recognized symptoms by which their presence
can be detected, or even suspected. In some cases the writer of
this work has detected more than a hundred small calculi in the
bladder of one ox.
Sometimes, however, they enter the duct (the cystic) which conveys
the bile to the intestines. They are likely to do this on account
of their swimming on the surface of the fluid whipl? the gall-bladder