222 DISEASES OF THE BRAIN 



Symptoms. — If encephalitis is secondary to feme specific 

 infectious disease the- symptoms of it may be masked by the 

 basic disorder. As a rule the cerebral symptoms which begin 

 either gradually or quite rapidly (hemorrhage) manifest 

 themselves as disturbance in consciousness. The patient 

 appears languid, stupid, more or less oblivious of its surround- 

 ings, and assumes unphysiological postures. The gait is 

 staggering or the patient may be down in a soporous or even 

 comatose condition. Sometimes in the horse the patient will 

 show symptoms of cerebral excitement or even rabiform 

 symptoms. These are usually followed, however, within a 

 short time by stupor. The patient may show forced movements. 



The topical symptoms are usually not determinable if there 

 is much mental depression. However, some of them may 

 be notable, such as paralysis of the pharynx, tongue, larynx, 

 eyelids, dilated pupils, etc. If the inflammation of the brain 

 is diffuse a general paresis may result, the patient being 

 unable to regain its feet when down or walk without support 

 when up. If the respiratory centre becomes involved fatal 

 dyspnea may result. The temperature is usually elevated 

 (105° F.), but the fever is mild and may be entirely absent in 

 protracted cases. The pulse is generally in harmony with the 

 temperature. Both are increased during the stage of excite- 

 ment. In the earliest stages the appetite is good, provided 

 the basic disease present has not already interfered. If the 

 mental depression is marked, however, the patient may 

 refuse to eat. 



Course. — The usual run of acute encephalitis is two to five 

 days. Subacute cases may last for weeks and chronic ones 

 for years, producing the so-called "dummy." 



When the development is rapid, disturbance in conscious- 

 ness soon appears. With the development of the mental 

 symptoms the topical symptoms usually keep pace. Re- 

 covery occurs exceptionally. In influenza the course is more 

 favorable. 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 animal's efficiency. 



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