the function of
locomotion by the hind leg who can comprehend the gravity of the only
prognosis which can be justified by the facts of the case--a prognosis
which is essentially a sentence of serious import in respect to the
future usefulness and value of the animal. For no disease, if we except
those acute inflammatory attacks upon vital organs to which the patient
succumbs at once, is more destructive to the usefulness and value of a
horse than a confirmed spavin. Serious in its inception, serious in its
progress, it is an ailment which, when once established, becomes a fixed
condition which there is no known means of dislodging.

_Cause._--The periostitis, of which it is nearly always a termination,
is usually the effect of a traumatic cause operating upon the
complicated structure of the hock, such as a sprain which has torn a
ligamentous insertion and lacerated some of its fibers, or a violent
effort in jumping, galloping, or trotting, to which the victim has been
compelled by the torture of whip and spur while in use as a gambling
implement by a sporting owner, under the pretext of "improving his
breed"; the extra exertion of starting an inordinately heavy load, or an
effort to recover his balance from a misstep, slipping upon an icy
surface, or sliding with worn shoes upon a bad pavement, and other
kindred causes. We can repeat here what we have before said concerning
bones, in respect to heredity as a cause. From our own experience we
know of equine families in which this condition has been transmitted
from generation to generation, and animals otherwise of excellent
conformation have been rendered valueless by the misfortune of a
congenital spavin.

_Symptoms._--The evil is one of the most serious character for other
reasons, among which may be specified the slowness of its development
and the insidiousness of its growth. Certain indefinite phenomena and
alarming changes and incidents furnish usually the only portents of
approaching trouble. Among these signs may be mentioned a peculiar
posture assumed by the patient while at rest, and becoming at length so
habitual that it can not fail to suggest the action of some hidden
disorder. The posture is due to the action of the adductor muscles, the
lower part of the leg being carried inward, and the heel of the shoe
resting on the toe of the opposite foot. Then an unwillingness may be
noticed in the animal to move from one side of the stall to the other.
When dri