195 



Symptoms. — Imperfect vision, constantly dilated pupils, frequently a 

 feeble and staggering gait, and occasionally cramps, convulsions, or 

 epileptic fits occur. 



Pathology. — Tlie exact opposite of cerebral hypersemia. The blood- 

 vessels are found empty, the membranes blanched, and the brain sub 

 stance softened. 



Treatment. — Kemoval of the remote cause when possible. General 

 tonics, nutritious food, rest, and removal from all causes of uervous 

 excitement. 



ATROPHY OF THE BRAIN. 



This condition is produced by a fault in nutrition, embracing the 

 causes which induce anosmia. Gradual absorption and shrinking of 

 brain substance may arise from the constant and increasing pressure 

 arising from the growth of tumors, degeneration in the arterial walls, 

 hydrocephalus, etc. AtrojDhy of the brain may be general or localized. 

 The cerebrum may waste away in a remarkable degree before any indi- 

 cation of disease becomes manifest. 



Symptoms. — It may give rise to viciousness, paralysis, disorders of 

 special sensation, coma, etc. Treatment is of no avail. 



HYDROCEPHALUS — BRAIN DROPSY. 



This disease is most often seen in young foals and is manifested by 

 an unnaturally large forehead. The forehead bulges out, and the cra- 

 nial bones may be separated from their connections, and a part of the 

 brain be covered by the skin only. Foals seldom survive this affection, 

 and treatment is useless. In horses hydrocephalus is a result of 

 chronic meningitis, when an effusion of serum is poured out into the 

 ventricles and arachnoid spaces of tbe brain. The disease is some- 

 times indicated by a difficulty in controlling voluntary movements, 

 coma, etc. When effusion as a result of meningitis is suspected, iodide 

 of potassa in 2-dram doses may be given twice a day and a strong 

 blister applied behind the ears. 



TUMORS WITHIN THE CRANIUM. 



Tumors within the cranial cavity and the brain occur not infrequently, 

 and give rise to a variety of symptoms, imperfect control of voluntary 

 movement, local paralysis, epilepsy, etc. 



Osseous tumors, growing from the walls of the cranium, are not very 

 uncommon. 



Dentigerous cysts, containing a formation identical to that of a tooth, 

 growing from the temporal bone, sometimes are found lying loose within 

 the cranium. 



Tumors of the choroid plexus, known as brain sand, are frequently met 

 with on postmortem examinations, but seldom give rise to any appreci- 



