PARALYSIS OF THE PERIPHERAL NERVES 451 



the nerve and destroy its function either by compression 

 or direct growth into it. (c) Inflammation of the middle 

 ear, caries of the petrous portion of the temporal bone, and 

 tumors in the base of the brain often produce it. (d) Dis- 

 temper (nervous form) producing an encephalitis will often 

 result in paralysis of the facial nerve, (e) Exposure to cold, 

 such as hunting dogs, or retrievers in which the surface of 

 the body is suddenly subjected to the extreme temperature. 



A bilateral facial paralysis (diplegia facialis) is usually 

 of central origin. 



Symptoms.— In case the entire nerve with all its branches 

 is paralyzed there will be paralysis of the ear, eyelids and 

 lips on the side affected. The ear will droop, and the animal 

 is unable to elevate it when called or excited. The eyelids 

 hang downward and are immovable. The lip will be found 

 soft, flabby and will not react to normal stimuli. When 

 these symptoms are present the lesion is central. On the 

 other hand, should there be a paralysis of the lips only, 

 it would indicate a peripheral form of facial paralysis. 

 Paralysis of the facial nerve arising from the central nervous 

 system may have associated with it paralysis of other cranial 

 nerves. This would complicate the symptoms. 



Diagnosis. —The symptoms are characteristic. A differ- 

 ential diagnosis should be made between central facial 

 paralysis and the peripheral form. This can be easily 

 determined in most cases by noting the extent of the paralysis. 



Prognosis.— When there is complete paralysis of central 

 origin it is considered unfavorable. However, if the con- 

 dition has only temporarily affected the nerve the animal 

 will recover. The exact condition of the nerve is impossible 

 to determine. In the peripheral form the condition of the 

 nerve at the point of injury is important. When not 

 destroyed the prognosis is favorable. 



Treatment.— In the peripheral form due to injury or chill- 

 ing, the symptoms usually disappear quite promptly. The 

 parts should be massaged thoroughly and the electric 

 current applied daily over the region. Stimulating lini- 

 ments massaged into the tissues are recommended (soap 

 liniment, camphor liniment, white liniment). If tumors 



