harnessed or bitted for the first few
times, should not have their heads checked high, for it frequently
causes them to rear up, and, being unable to control their balance, they
are liable to fall over sideways or backwards, thus causing brain
concussion when they strike the ground.

ANEMIA OF THE BRAIN.

This is a physiological condition in sleep. It is considered a disease
or may give rise to disease when the circulation and blood supply of the
brain are interfered with. In some diseases of the heart the brain
becomes anemic, and fainting fits occur, with temporary loss of
consciousness. Tumors growing within the cranium may press upon one or
more arteries and stop the supply of blood to certain parts of the
brain, thus inducing anemia, ultimately atrophy, softening, or
suppuration. Probably the most frequent cause is found in plugging, or
occlusion, of the arteries by a blood clot.

_Symptoms._--Imperfect vision, constantly dilated pupils, frequently a
feeble and staggering gait, and occasionally cramps, convulsions, or
epileptic fits occur.

_Pathology._--The exact opposite of cerebral hyperemia. The blood
vessels are found empty, the membranes blanched, and the brain substance
softened.

_Treatment._--Removal of the remote cause when possible. General tonics,
nutritious feed, rest, and removal from all causes of nervous
excitement.

HYDROCEPHALUS, OR DROPSY OF THE BRAIN.

This condition consists in an unnatural collection of fluid about or in
the brain. Depending upon the location of the fluid, we speak of
external and internal hydrocephalus.

External hydrocephalus is seen chiefly in young animals. It consists in
a collection of fluid under the meninges, but outside the brain proper.
This defect is usually congenital. It is accompanied with an
enlargement of the skull, especially in the region of the forehead. The
pressure of the fluid may cause the bones to soften. The disease is
incurable and usually fatal.

Internal hydrocephalus is a disease of mature horses, and consists in
the accumulation of an excessive quantity of fluid in the cavities or
ventricles of the cerebrum. The cause of this accumulation may be a
previous inflammation, a defect in the circulation of blood through the
brain, heat stroke, overwork, excessive nutrition, or long-continued
indigestion. Common, heavy-headed draft horses are predisposed to this
condition.

_Symptoms._--The symptoms are an expression of dullness and stu