DISEASES OF THE BRAIN. 201 



sudden paralysis of some part of the body is the result. The extent 

 and location of the paralysis depend upon the location within the 

 brain which is functionally deranged by the pressure of the extrava- 

 sated blood ; hence these conditions are very variable. 



In the absence of any premonitory symptoms or an increase of tem- 

 l^erature in the early stage of the attack, we may be reasonably certain 

 in making the distinction between this disease and congestion of the 

 brain, or sunstroke. 



Pathology. — In apoplexy there is generally found an atheromatous 

 condition of the cerebral vessels, with weakening and degeneration of 

 their walls. When a large artery has been ruptured it is usually fol- 

 lowed by immediate death, and large rents maj' be found in the cere- 

 brum, with great destruction of brain tissue, induced by the forcible 

 pressure of the liberated blood. In small extravasations producing 

 local paralysis without marked general disturbance, the animal may 

 recover after a time ; in sucli cases gradual absorption of the clot takes 

 place. In large clots atrophy of the brain substances ma}^ follow, or 

 softening and abscess from want of nutrition may result, and render 

 the animal worthless, ultimateh' resulting in death. 



Treatment. — Place the animal in a quiet, cool place and avoid all 

 stimulating food. Administer, in his drinking water or feed, 2 drams 

 of the iodide of potassa twice a day for several weeks if necessary. 

 Medical interference with sedatives or stimulants is more apt to be 

 harmful than of benefit, and bloodletting in an apoplectic fit is 

 extremely hazardous. From the fact that cerebral apoplexy is due to 

 diseased or weakened blood vessels, the animal remains subject to 

 subsequent attacks. 



COMPRESSION OF THE BRAIN. 



Causes. — In injuries from direct violence a j^iece of broken bone 

 may press upon the brain, and, according to its size, the brain is 

 robbed of its normal space within the cranium. It may also be due 

 to an extravasation of blood or to exudation in the subdural or arach- 

 noid spaces. Death from active cerebral congestion results through 

 compression. The occurrence ma}^ sometimes be traced to the direct 

 cause, which will give assurance for the correct diagnosis. 



Sy77ipto?ns. — Impairment of all the special senses and localized 

 paralysis. All the symptoms of lessened* functional activity of the 

 brain are manifested to some degree. The paralysis remains to be 

 CHir guide for the location of the cause, for it will be found that the 

 paralysis occurs on the opposite side of the body from the location of 

 the injury, and the parts suffering paralysis will denote, to an expert 

 veterinarian or physician, the part of the brain which is suffering 

 compression. 



Treatment. — Trephining, by a skillful operator, for the removal of 



