454 DISEASES OF THE PERIPHERAL NERVES 



minor importance are: Concussion of the brain, hemor- 

 rhages in the middle ear, or caries of the petrous portion 

 of the temporal bone. 



Symptoms.— Deafness is the pronounced symptom of 

 paralysis of the cochlear nerve. If bilateral and complete 

 the animal will be totally deaf. In vestibular paralysis, 

 when unilateral, the patient will assume a peculiar attitude 

 holding the head downward and toward the normal side. 

 In chickens the head is rotated to the degree that the comb 

 will rest on the ground. In dogs and rabbits rolling move- 

 ments are very prominent symptoms. This is so marked 

 in some cases that it is impossible to hold the animal. The 

 least irritation or disturbance will cause them to show it. 

 Rolling movements always take place toward the normal 

 side. Attempts at walking are difficult but if they succeed 

 will travel in circles, often falling down and rolling over 

 and over. The eyelids are often closed and the eyeball 

 assumes an abnormal position. In case of bilateral vestib- 

 ular paralysis, the head drops down and the muscles of 

 the neck are limp. 



Diagnosis.— This should not be difficult, as the symptoms 

 of deafness are easily manifest and the peculiar movements 

 of the animal in vestibular paralysis are characteristic. 



Prognosis.— Should be considered unfavorable except when 

 due to injuries. 



Treatment.— If due to injuries the animal should be kept 

 quiet and if necessary fed artificially in order to maintain 

 its general condition. The ears should always be exam- 

 ined to determine their condition (disease or parasites). 

 Pigeons, when affected, are isolated and the premises dis- 

 infected to guard against contagious meningitis. Internal 

 administration of magnesium sulphate or castor oil as a 

 laxative is advised. No treatment can be applied direct 

 to the seat of the condition. 



Radial Nerve.— Paralysis of this nerve occurs occasionally 

 in the dog and cat. 



Etiology. — (a) On account of the position of the radial 

 nerve it is easily injured by traumatism. Animals struck 

 by objects, falling, jumping, etc., very commonly injure 



