ENCEPHALITIS— INFLAMMATION OF THE BRAIN 243 



ness soon appears. With the development of the mental 

 symptoms the topical symptoms usually keep pace. Recov- 

 ery occurs exceptionally. In influenza the course is more 

 f avoraye. Cases which do not die usually lead to the patient 

 becoming a "' dummy" which not infrequently suffers from a 

 temporary return of the encephalitic symptoms. If topical 

 symptoms are left behind obviously they may interfere with 

 the animals' efficiency. 



Diagnosis. — ^The diagnosis depends upon the symptoms of 

 a severe brain distm-bance with which are associated well- 

 defined topical symptoms, such as hemiplegia, monoplegia, 

 ataxia, facial paralysis, etc. If these symptoms occur with 

 or follow an infectious disease with which a non-suppurative 

 encephalitis is apt to occur a diagnosis is possible. On the 

 other hand, primary encephalitis is quite difficult to diagnose 

 unless both the general and topical sjTnptoms are well 

 developed. From purulent encephalitis the non-suppura- 

 tive form can usually be distinguished by the absence of 

 injury to the craniimi or the absence of a primary abscess 

 in some removed organ or in the cranial wall. It may be 

 impossible to distinguish between encephalitis and meningo- 

 encephalitis in those cases of encephalitis in which the 

 topical symptoms fail. Furthermore, in some cases of 

 encephalitis the meninges may be also involved. Encepha- 

 litis is distinguished from chronic hydrocephalus by its 

 more sudden development, the severity of the brain symp- 

 toms, and the presence of topical symptoms. Encephalitis 

 usually follows some infectious disease. From forage 

 poisoning encephalitis is distinguished by the severity of 

 the brain symptoms, the sporadic appearance of the dis- 

 ease, the absence of intestinal symptoms, and no history 

 of the animals having eaten food which was moldy or 

 otherwise spoiled. 



Treatment. — The treatment is the same as for meningo- 

 encephalitis, and is usually of little aid to recovery. 



Suppurative Encephalitis. — {Abscess of the Brain.) — Occur- 

 rence. — Brain abscesses are most apt to occur in young 

 horses. In the other domesticated animals abscess of the 

 brain is extremely rare. 



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