DISEASES OF THE BRAIN. 207 



ity that could be found, and consequently furnishes its own remedy 

 so far as the continuance of the convulsive paroxysm is concerned. 

 Whatever treatment is instituted must be directed toward a removal 

 of the cause of the convulsive paroxysm. 



CHOEEA, OE ST. VITUS DAKCE. 



Chorea is characterized by involuntary contractions of voluntary 

 muscles. This disease is an obscure disorder, which may be due to 

 pressure upon a nerve, cerebral, or spinal sclerosis, small aneurisms 

 in the brain, etc. Choreic symptoms have been produced by injecting 

 granules of starch into the arteries entering the brain. Epilepsy and 

 other forms of convulsions simulate chorea in appearance. 



Stringhalt is by some termed chorea. This is manifested by a sud- 

 den jerking up of one or both hind legs when the animal is walking. 

 This symptom may be very slight in some horses, but has a tendency 

 to increase with the age of the animal. In some the catching up of 

 the affected leg is very violent, and when it is lowered to the ground 

 the motion is equally sudden and forcible, striking the foot to the 

 ground like a pile driver. Very rarely chorea may be found to affect 

 one of the fore legs, or the muscles of one side of the neck or the 

 upper part of the neck. Involuntary jerking of the muscles of the 

 hip or thigh is seen occasionally, and is termed " shivering " by 

 horsemen. 



Chorea is often associated with a nervous disposition, and is not so 

 frequent in animals with a sluggish temperament. The involuntary 

 muscular contractions cause no pain, and do not appear to produce 

 much exhaustion of the affected muscles, although the jerking may be 

 regular and persistent whenever the animal is in motion. 



Treatment. — In a few cases, early in the appearance of this affec- 

 tion, general nerve tonics may be of benefit, viz, iodide of iron, 1 

 dram ; pulverized nux vomica, 1 dram ; pulverized Scutellaria, 1 ounce. 

 Mix and give in the feed once a day for two weeks. Arsenic in the 

 form of Fowler's solution is often beneficial. If the cause is con- 

 nected with organic brain lesions, treatment is usually unsuccessful. 



EPILEPSY, OK FALLING FITS. 



The cause of epilepsy is seldom traceable to any special brain lesions. 

 In a few cases it accompanies disease of the pituitary body, which is 

 located in the under surface of the brain. Softening of the brain 

 may give rise to this affection. Attacks may occur only once or twice 

 a year or they may be of frequent recurrence. 



Symptoms. — ^No premonitory symptoms precede an epileptic fit. 

 The animal suddenly staggers; the muscles become cramped; the 

 jaws may be spasmodically opened and closed, and the tongue be- 



