200 DISEASES OF THE NEB VO US SYSTEM. 



would direct our readers to some one of the various physiological 

 text-books. 



The most important peripheric paralyses which have beea 

 observed in the dog (by traumatism, compression, or exudation, 

 inflammatory or degenerating processes of the affected nerves) are 

 as follows: 



1. Motor Trigeminal Paralysis. (Paralysis of the lower jaw.) The 

 lower jaw hangs down ; mastication is impossible; saliva runs 

 out of the mouth. This condition occurs very frequently as a 

 symptom of rabies. In rare instances it has been observed as a 

 result of some other disease. 



2. Paralysis of the Anterior Limbs. The front legs hang inert 

 and all the joints flex very easily. 



3. Paralysis of the Posterior Limbs. The hindlegs are dragged 

 along the ground, the paws being flexed and drawn backward. 

 If the paws are drawn forward and this flexion overcome, the 

 animal is able to stand on its legs if the body is held. 



4. Paralysis of the Cruralis. In this condition the animal does 

 not use the posterior limb. All the joints become flexed abnor- 

 mally, and the thigh bends backward. This condition may also 

 be due to some disease of the spine. 



The most important test of paralyzed muscles is their size. In 

 all cases of prolonged paralysis the muscles atrophy quickly. The 

 muscle gradually becomes smaller and smaller until it resembles a. 

 cord or tendon. In cerebral paralysis this does not occur, while 

 in spinal paralysis it is always present. Of course, in some in- 

 stances an inactive muscle will atrophy without any actual disease 

 being present. The amount of atrophy which may occur in cer- 

 tain cases is indicated by a communication given to the author by 

 Goubau.v. In this instance the paralyzed anterior limb of a dog 

 weighed 103 grammes, while the perfect limb weighed 148 

 grammes. 



Convulsions. Convulsion of the controlling muscles is the 

 very opposite of paralysis. Convulsions are diseased contractions 

 of the muscles which are independent of the will. There are 

 several varieties of them. Clonic convulsions are short muscular 

 contractions that occur at intervals, and between the intervals the 

 affected portion of the body quivers constantly. Tonic convul- 

 sions are muscular contractions in which the muscle remains con- 



