726 Spasm uf Uie Facial Nerve. Paralysis of the Aiulitoiy Nerve. 



the teeth and the cheeks should be removed. If the usefuhiess 

 of the animal is impaired owing to bilateral narrowing of the 

 nostrils the collapse of the paralyzed nostrils may be prevented 

 by sutures or tracheotomy may afford relief. 



Literature. Cadeac, J. Vet., 1902, 526.— Dexler, Monh., 1896, VII, 193; 

 Nervenkrkh. d. Pferdes, 1899, 27 (Lit.) ; Ergebn. d. Path., 1900, VII, 4.58.— Dupas, 

 Bull., 1904, 527.— Dutrev, Ann., 1906, 339.— Muller, S. B., 1900, 261.— Pr. Mil. Vb., 

 ISitO, 97.— Pesadory, (n'in. Vet., 1906, 543.— Eeinshagen, Pr. Vb., 1904, II, 62.— 

 Vosshage, D. t. W.", 1902, 483. 



Spasm of the Facial Nerve. This occurs with moderate frequency 

 in dogs as a result of encephalitis, due to distemper, the cause being 

 inflammation in the neighborhood of the nucleus of the nerve. In a 

 case carefully investigated by Cadiot, Gilbert and Roger, the contrac- 

 tions remained unaltered after destruction of the paths leading to the 

 nucleus of the facial nerve, but disappeared after destruction of that 

 nucleus. The condition has also been observed in cases of meningitis 

 and other forms of encephalitis, and apparently also in cases of simple 

 neurosis. In all these cases, there are clonic spasms of the muscles 

 supplied 1)y the nerve, while in tetanus there are generally tonic 

 spasms. 



4. Paralysis of the Auditory Nerve. 



Etiology. Paralysis of the cochlear nerve, the true organ 

 of hearing, is a congenital defect in albinotic animals and is due 

 to a defective condition of the spiral ganglion with resulting de- 

 generation of the organ of Corti (Alexander, Tandler, Beyer). 

 Paralysis of the nerve may also be caused by inflammatory 

 changes in the internal ear (Jakob), or intracranial disease in 

 the neighborhood of the medulla oblongata. 



Paralysis of the vestibular nerve is frequently observed in 

 dogs, pigs, rabbits and birds. It is often caused by inflamma- 

 tion of the middle and internal ear as in swine plague (Berg- 

 mann), in contagious rhinitis, inflammation of the nose caused 

 by coccidia, and in chicken pest. The paralysis may also be 

 caused by inflammation or caries of the petrous temporal bone. 

 Other causes are: concussion of the brain (see page 623), and 

 liemorrhages of the internal ear caused in a similar manner. 

 Other diseases of the medulla or the cerebellum may cause in- 

 terruption in the conductivity of the vestibular nerve. In pi- 

 geons it is observed in cases of contagious meningitis (megrims). 



Symptoms. Bilateral disease of the cochlear nerve is easily 

 recognized owing to complete deafness, but if the disease be 

 unilateral it generally escapes the owner's notice and is very 

 difficult to demonstrate. 



Unilateral paralysis of the vestibular nerve is evidenced in 

 all species by the head being held in an oblique position, the dis- 



