FACIAL PARALYSIS. 
7 
easily injure the nerve when the animal is lying. The double-sided 
paralysis described by Grebe, and erroneously regarded as reflex paralysis, 
is similarly produced. In earlier times, facial paralysis was often caused 
by inserting hair setons in the cheeks as a remedy in diseases of the eye. 
It occurs during the progress of serious infectious disorders, such as 
influenza, petechial fever, &c., and may also be produced, as in man, by 
severe chills. Utz saw the condition after an animal had been struck 
by lightning. 
The paralysis is mostly confined to the facial muscles. The lips are 
distorted, the nostrils narrowed, the upper lip, and sometimes the under, 
are drawn towards the sound side. The condition is best recognised by 
looking at the lips from in front. So long as one side alone is affected, 
feeding is little interfered with ; but in double-sided paralysis the lips 
hang flaccid, a condition best seen in the under lip, and feeding now 
becomes extremely difficult. The food can only be grasped with the 
teeth, and, in drinking, the corners of the mouth must be immersed in 
order to prevent the water flowing back. Even when carefully tended, 
the animals rapidly loose condition, for they have difficulty not only 
in grasping food, but, owing to the paralysis of the cheeks, also in 
masticating it. The food cannot be brought between the opposing rows 
of teeth and so accumulates between the cheek and molars. These are 
the appearances when injury has occurred at the point where the nerve 
passes round the under jaw; but where in addition the subzygomatic 
nerve is involved, sensation is lost in the skin of the affected side. 
Facial paralysis due to central injury is different both in its symptoms 
and consequences. Should the lesion be sufficiently near the brain to 
involve the zygomatico-temporalis nerve, then, in addition to the above 
appearances, paralysis affects the levator palpebrarum, as well as various 
muscles of the ear. The upper eyelid will droop (ptosis) whilst the 
orbicularis palpebrarum will be unable to properly close the eye, and the 
ear on the affected side will hang limply. (Fig. 2.) Zahn found the 
bulbus of the affected side smaller, and the cornea cloudy. Disturbance 
of hearing could also be detected. Not infrequently paralysis of other 
portions of the body accompanies paralysis of the facial; thus Jewtichilew 
saw hemiplegia, Tempel paralysis of the trigeminal nerve, and Fuchs of 
the hypoglossus and glossopharyngeus. 
The causes are various. Melanotic tumours, developing in the parotid, 
as well as swellings in the Fallopian canal, may press on the nerve. 
Occasionally the origin is central. Thus the post-mortem of a horse 
suffering from double-sided paralysis, disclosed sarcoma of the pons. 
Gotze noted paralysis of the lips and ears in a horse after influenza, and 
found on section an abscess in the cerebellum. In another case, Lydtin 
saw sarcoma on the petrous temporal bone, the growth extending from 
