and
mingled with masses of clotted casein. Later it becomes white and purulent,
and in many cases of an offensive odor.

The course of the disease is sometimes so rapid and at others so slow that
no definite rule can be laid down. In two or three days, or from that to
the end of the week, the bag may soften, lose its heat and tenderness, and
subside into the healthy condition, even resuming the secretion of milk.
The longer the inflammatory hardness continues the greater the probability
that its complete restoration will not be effected. When a portion of the
gland fails to be restored in this way, and has its secretion arrested, it
usually shrinks to a smaller size. More commonly a greater quantity of the
inflammatory product remains in the gland and develops into a solid,
fibrous mass, causing permanent hardening (induration). In other cases, in
place of the product of inflammation developing into a fibrous mass, it
softens and breaks down into white, creamy, liquid pus (abscess). This
abscess may make its way to the surface and escape externally, or it may
burst into a milk duct and discharge through the teat. It may break into
both and establish a channel for the escape of milk (fistula). In the worst
types of the disease gangrene may ensue, a quarter or half or even the
whole udder, losing its vitality, and sloughing off if the cow can bear up
against the depressing influence. These gangrenous cases are probably
always the result of infection and sometimes run a very rapidly fatal
course. I remember one to which I was called as soon as the owner noticed
it, yet I found one-quarter dark blue, cold, and showing a tendency to the
formation of blebs containing a bloody secretion. The cow, which had waded
through a depth of semiliquid manure to reach her stall, died within 24
hours.

_Treatment._--Treatment varies with the type and the stage of the disease.
If the case is seen in the shivering fit, every effort should be made to
cut it short, as the inflammation may be thereby greatly moderated, if not
checked. Copious drinks of warm water thrown in from horn or bottle;
equally copious warm injections; the application of heat in some form to
the surface of the body (by a rug wrung out of hot water; by hanging over
the back and loins bags loosely filled with bran, sand, salt, chaff, or
other agent previously heated in a stove; by the use of a flatiron or the
warming of the surface by a hot-air bath), or by active fricti