458 NERVOUS SYSTEM. 



Prognosis. Sooner or later the case is likely to end fatally, and 

 there is no practical use in treating the patient. 



Treatment. If in exceptional cases slaughter is objected to, setons 

 and blisters may be applied to the poll or the parotid region, or the 

 parts may be enveloped in ice bags or compresses of iced water 

 frequently renewed. 



ENCEPHALITIS. 



Encephalitis, i.e., inflammation of the cerebral substance, is very 

 closely allied to meningitis ; in a great number of cases meningitis 

 and encephalitis co-exist. In other cases encephalitis may be found 

 apart from meningitis, and vice versa. Moreover, many of the symp- 

 toms of meningitis are to be found in cases of encephalitis. 



Encephalitis may develop as a complication of meningitis. Ence- 

 phalitis may also follow abundant parasitic infestation, as in coenurosis 

 (which will be particularly studied as it affects sheep), or microbic 

 infection, the commonest form of which in the ox is tuberculosis. 

 The encephalitis may be diffuse or circumscribed, according to the 

 cause, while the symptoms are varied and numerous. Very frequently, 

 particularly in cases of tuberculosis, encephalitis assumes a chronic 

 form. 



Symptoms. The earliest symptoms are extremely difficult to detect, 

 because they are scarcely characteristic and because it is impossible 

 to ascertain the sensations of the animal. 



It is only when the disturbances in walking, in the eyesight, in 

 swallowing, etc., are noted that suspicion is aroused. 



The symptoms may appear suddenly. Nevertheless it is beyond 

 doubt that there are certain slightly marked prodromata, indicated by 

 diminution of appetite, wasting, and changes in vision. Soon afterwards 

 occur other forms of disturbance, which may be classified under the 

 heading of " motor, visual, nervous, and impulsive." The patients 

 appear stunned, their movements are slow and hesitating, they par- 

 tially lose control over their limbs and display lameness, with spasmodic 

 movements of one or two limbs. Examination of the joints shows no 

 injury. The lameness may simultaneously affect two diagonal limbs 

 or two fore and two hind limbs, or even three limbs. This lameness 

 is of central origin. 



The ocular disturbance is marked by diminution or loss of vision, 

 by strabismus, or by frequent unconscious movements of the eyes and 

 eyelids, and also more particularly by inequality, contraction or dila- 

 tation of the pupils. 



Nervous, impulsive disturbance is most readily noted when the 

 animals are at liberty. Even when the sight remains, they seem 



