DISEASES OF THE NERVOUS SYSTEM. 167 



COXVULSIOJYS. 



Convulsions and fits are terms used synonymously and signify a sudden 

 seizure, loss of consciousness, involuntary, spasmodic contractions of the 

 muscles of the body, foaming at the mouth, followed by stupor. 



Convulsions among dogs, and more especially in early life, are of fre- 

 quent occurrence. Epilepsy is the more common term used among writers 

 on canine diseases to designate these attacks; it should more properly be 

 restricted to those purely functional in character, that is, not necessarily 

 attended with either inflammation or appreciable disease of structure, 

 and distinguished by a chronic course and unexpected recurrence. 



Convulsions do not represent any single form of disease. Among the 

 number of morbid conditions which may induce them some are determin- 

 able, others are obscure, and of them we possess little positive knowledge. 



Causation. —Predisposition plays a prominent part in the production 

 of numerous forms of convulsion ; it may be inherited, or acquired through 

 the action of various conditions and diseases. 



Nervous disorders are more easily generated in some breeds of dogs 

 than in others, and in-breeding among such cannot lessen the liability. 

 General debility, changes in the blood, age, and diseases incident to par- 

 turition, appear strongly to favor a predisposition. 



Among the exciting causes may be mentioned worms, the eruption of 

 the teeth, over exertion, intense heat, fear, anger, and witnessing other 

 convulsions. Prof. Dalton has related the following illustration of the 

 effect of imitation in the canine race. A dog, not previously affected with 

 epilepsy, was in company with another clog which was subject to the affec- 

 tion; the latter being seized with a convulsion, the former immediately 

 afterward had a similar attack. 



Among the causes exciting convulsions may be mentioned numerous 

 poisons, strychnine, etc.; injuries to the brain and spine; in fact very 

 many irritations and inflammations in different parts of the body, and 

 derangements and diseases of the internal organs may give rise to the 

 affection. 



Symptoms.— Convulsions come on abruptly and without symptoms 

 indicative of their onset. If the dog is at exercise, he stops suddenly, 

 remains for an instant fixed to the spot as it were, his legs tremble, utter- 

 ing a short, sharp cry or a low moan he falls, possibly attempts to rise 

 again, again falls, becomes unconscious, and convulsive movements at 

 once begin. More often they are at first what are termed tonic spasms, 

 that is a persistent and uniform muscular contraction of great intensity, 

 lasting usually for a few seconds, followed by spasms for which the name 

 clonic is given. By this it is understood a rapid succession of contractions 



