DISEASES OF THE NERVOUS SYSTEM. 223 
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. Bleed- 
ing, 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.—Y oung horses, when harnessed or bitted for the first 
few times, should not have their heads checked high, for it fre- 
quently 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 tem- 
porary 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 sub- 
stance 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 apinialas It. com- 
sists in a collection of fluid under the meninges, but outside the brain 
proper. This defect is usually congenital. It is accompanied with 
