impede normal
movement.

AFFECTIONS OF BONES.

The bony column serving as the framework and support of the legs,
probably constitutes the most vital element having to do with weight
bearing and locomotion, and therefore during the acute and painful stage
of bone affections, the pain becomes more intense in the process and
pressure of standing than when the member is swung or advanced.

Certain bones are so well protected by muscular structures that they are
not frequently injured except as a result of violence which may produce
fracture. However, there are certain bones which receive the constant
shock of concussion when the animal is subjected to daily, rapid work on
hard road surfaces. Splints, ringbones and spavins are the most general
examples produced by these conditions.

Varying pathological developments often result from concussion,
contusion or other violent shocks to the bony structures. In such cases
there either follows a simple periostitis which may resolve
spontaneously with no obvious outward symptom, or osteitis, which may
occur with tissue changes, as in exostosis; or the case may produce any
degree of reaction between these two possible extremes.

Rarefying Osteitis, or Degenerative Changes.

Certain bone affections, such as osteomalacia or osteoporosis, are in
the main, responsible for distortions and morphological changes of bone,
causing lameness, permanent blemish and even resulting in death of the
affected animal. The climatic conditions in some localities favor these
occurrences but they may also be ascribed to improper food constituents
and to possible infective agencies.

Rarefying degenerative changes manifested by exostosis involving the
phalanges of the young, causing ringbone, are fairly common in
occurrence throughout this country. This is due, supposedly, to a lack
of mineral substance in the bony structure of the affected animals, and
is known as rachitis--commonly called rickets. Since the affected
subjects suffer involvement of several of the extremities at the same
time, the theory of rachitic origin seems well supported.

Fractures.

Fractures of bones constitute serious conditions and are always
manifested by lameness. A sub-classification is essential here for the
student of veterinary medicine who would comprehend the technic of
reduction and subsequent treatment in such cases.

Fractures are classified by many authorities as being _simple_,
_compound_, and _com