his fact can, as a rule, be determined at once by a thorough microscopic
examination of the blood. The necessary apparatus and the requisite
qualifications for this task leave this method entirely in the hands of
experts. There are, however, a considerable number of changes caused by
this disease which may be detected by the naked eye when the body has been
opened. Put together they make a mistake quite impossible. The presence of
small ticks on the skin of the escutcheon, the thighs, and the udder is a
very important sign in herds north of the Texas-fever line, as it indicates
that they have been brought in some manner from the South and have carried
the disease with them, as will be explained later. Another very important
sign is the thin, watery condition of the blood, either just before death
or when the fever has been present for four or five days. A little incision
into the skin will enable any one to determine this point. Frequently the
skin is so poor in blood that it may require several incisions to draw a
drop or more.
The changes in the internal organs, as found on post-mortem examinations,
are briefly as follows: The spleen, or milt, is much larger than in healthy
animals. It may weigh three or four times as much. When it is incised the
contents or pulp is blackish (see Pl. XLIV, fig. 1), and may even well out
as a disintegrated mass. The markings of the healthy spleen (fig. 2) are
all effaced by the enormous number of blood corpuscles which have collected
in it, and to which the enlargement is attributable. Next to the spleen the
liver will arouse our attention. (See Pl. XLV, fig. 2.) It is larger than
in the healthy state, has lost its natural brownish color (fig. 1), and now
has on the surface a paler, yellowish hue. When it is incised this
yellowish tinge, or mahogany color, as it has been called by some, is still
more prominent. This is owing to the large quantity of bile in the finest
bile capillaries, and as these are not uniformly filled with it the cut
surface has a more or less mottled appearance. This bile injection causes
in many cases a fatty degeneration of the liver cells, which makes the
organ appear still lighter in color.
In all cases the gall bladder should be examined. This is distended with
bile, which holds in suspension a large number of yellow flakes, so that
when it is poured into a tall bottle to settle fully one-half or more of
the column of fluid will be occupied by a layer of fl
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