CHAPTER III. 



DISEASES OF THE PERIPHERAL NERVOUS 



SYSTEM. 



INJURIES OF THE PERIPHERAL NERVES. 



Small animals are subjected to a variety of injuries which 

 may involve the individual nerves or nerve endings, such 

 as bruises of the muscles, in which the nerve is crushed 

 against the bones, or between muscles, or stretched or torn 

 or the nerve is cut by sharp objects which is more frequent. 



PRESSURE UPON THE PERIPHERAL NERVES. 

 COMPRESSION. 



Most frequently compression results from neoplastic 

 formations (sarcomas, neuromas), from hemorrhagic extrav- 

 asations, serous effusions into the tissues, enlargement of 

 lymph glands, fractures of bones or abscess formation. 



Neuritis undoubtedly occurs in small animals, particu- 

 larly in dogs, and may result from a variety of causes. 

 Chilling or subjection to extremes of temperature is 

 perhaps most productive of the condition. The inflam- 

 mation resulting is subsequently followed by paralysis in 

 a number of cases. 



PARALYSIS OF THE PERIPHERAL NERVES. 



The following paralyses of peripheral nerves have been 

 noted : 



Facial Nerve.— Dogs and rabbits are most often affected. 



Etiology. — (a) Traumatic influences play an important role 

 in the unilateral form of facial paralysis (monoplegia facialis) 

 by injuring the nerve at the point where it goes around the 

 maxillary bone. (6) Neoplasms in the parotid region involve 



