region is
affected.

The sudden manifestation of lameness is indicative of injury; thermic
disturbances may signalize metastatic infection; history, if dependable,
is always helpful. Repeated observations, taking into account the course
which the affection assumes during a period of a few days, often serve
to afford a means of establishing a diagnosis in baffling cases.

Fractures of the Pelvic Bones.

The os innominatum may be so fractured that the pelvic girdle is broken,
as in fracture of the iliac shaft, or in a manner that the girdling
continuity of the innominate bones is not interrupted. It naturally
follows that greater injury is done when the pelvic girdle is broken
than when it is not, except in cases where the acetabulum is involved
and its brim not completely divided.

Etiology and Occurrence.--Pelvic fractures are usually caused by falls
or other manner of contusion. Cases are reported where it would seem
that fracture of the iliac angle resulted from muscular contraction, but
it is certain that most fractures of this kind are due to collisions
with door jambs or similar injuries. In old horses especially, fracture
of pelvic bones occurs frequently. This form of injury is of more
frequent occurrence in animals of all ages that work on paved streets.
The country horse is not subjected to the uncertain footing of the
slippery pavement, nor to injuries which compare with those caused by
contusions sustained in falling upon asphalt or cobble-stones.

Symptomatology.--While in many cases of pelvic fracture lameness or
abnormal decumbency are the salient manifestations, yet the pathognomic
symptoms are crepitation or palpable evidence which may be obtained by
rectal or vaginal examination. In fractures of the angle of the ilium
and the ischial tuberosity, perceptible evidence always exists.

In cases where fracture of some portion of the pelvic girdle is
suspected and the subject is able to walk, crepitation is sought by
placing one hand on an external angle of the ilium and the other on the
ischial tuberosity and the animal is then made to walk. Or, by placing
the hands as just directed, an assistant may grasp the horse's tail and
by alternately exerting traction on the tail and pushing against the hip
in such manner that weight is shifted from one leg to the other,
crepitation may be detected.

Fracture of the pubis near its symphysis constitutes a grave injury, as
there is danger of the bladder becom