BRAIN TUMORS 249 



Treatment. — ^Treatment is of no avail. The efficiency of 

 the animal may, however, be prolonged by feeding only light, 

 laxative food and giving the patient good care. To relieve 

 constipation, salts should be given, and during an exacerba- 

 tion, hypodermic injections of pilocarpin (grs. iv to vj) or 

 arecalin (grs. j to ij) afford relief. 



BRAIN TUMOES. 



In animals brain timiors are comparatively rare. In the 

 horse the cholesteatoma has been noted quite frequently on 

 necropsy. During life it rarely produces symptoms. The 

 tmnor varies in size from a pea to a hen's egg. Other-tumors 

 occiu'ring in the brain substance are gliomas, gliosarcomas, 

 melanosarcomas, and very rarely carcinomas. Some of the 

 chronic infectious diseases may produce growths in the brain, 

 such as tuberculosis, actinomycosis and botryomycosis. 



In the meninges, fibromas, lipomas, angiomas, sarcomas, 

 epitheliomas, papillomas, and dermoid cysts have been noted. 



Symptoms. — Due to the slow growth of brain tumors they 

 rarely produce any sjinptoms during hfe. A tumor the size 

 of a hen's egg (melanoma) has been found in the brain of 

 a horse without the animal seeming in any way disturbed 



In rare instances brain tumors may produce periodical 

 increases in intracranial tension, especially after vigorous 

 exercise, causing symptoms of transient cerebral excitement, 

 followed by depression or the patient may show symptoms of 

 chronic hydrocephalus. More rarely the sj^mptoms closely 

 simulate acute meningo-encephalitis or encephalitis, the 

 animal dying in a short time. Sometimes brain tumors pro- 

 duce epileptiform seizures, cerebral ataxia, forced movements, 

 hemiplegia, blindness, and an abnormal carriage of the head. 

 Congestion of the papilla is thought by some observers sig- 

 nificant of brain tumor, and is a probable cause of the blind- 

 ness (amaurosis). 



Diagnosis. — ^The diagnosis is obviously extremely difficult. 

 The gradual development of the symptoms, both general and 

 topical, the congestion of the papilla, and the absence of 



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