er, succeeding immediately
upon a blow or severe injury involving the cranium. The animal may rally
quickly or not for hours; death may occur on the spot or after a few
days. When there is only slight concussion or stunning, the animal soon
recovers from the shock. When more severe, insensibility may be complete
and continue for a considerable time; the animal lies as if in a deep
sleep; the pupils are insensible to light; the pulse fluttering or
feeble; the surface of the body cold, muscles relaxed, and the breathing
scarcely perceptible. After a variable interval partial recovery may
take place, which is marked by paralysis of some parts of the body,
often of a limb, the lips, ear, etc. Convalescence is usually tedious,
and frequently permanent impairment of some organs remains.

_Pathology._--Concussion produces laceration of the brain, or at least a
jarring of the nervous elements, which, if not sufficiently severe to
produce sudden death, may lead to softening or inflammation, with their
respective symptoms of functional derangement.

_Treatment._--The first object in treatment will be to establish
reaction or to arouse the feeble and weakening heart. This can often be
accomplished by dashing cold water on the head and body of the animal;
frequent injections of weak ammonia water, ginger tea, or oil and
turpentine should be given per rectum. In the majority of cases this
will soon bring the horse to a state of consciousness. In more severe
cases mustard poultices should be applied along the spine and above the
fetlocks. As soon as the animal gains partial consciousness stimulants,
in the form of whisky or capsicum tea, should be given. Owing to
severity of the structural injury to the brain or the possible rupture
of blood vessels and blood extravasation, the reaction may often be
followed by encephalitis or cerebritis, and will then have to be treated
accordingly. For this reason the stimulants should not be administered
too freely, and they must be abandoned as soon as reaction is
established. There is no need for further treatment unless complications
develop as a secondary result. Bleeding, which is so often practiced,
proves almost invariably fatal in this form of brain affection. We
should also remember that it is never safe to drench a horse with large
quantities of medicine when he is unconscious, for he is very liable to
draw the medicine into the lungs in inspiration.

_Prevention._--Young horses, when