218 PKACTICE OF EQUINE MEDICINE. 



CHOEEA. 



What are the synonyms ? 



St. Yitus's Dance; insanity of muscles; twitching disease; 

 stringhalt in the horse. 



Define chorea. 



This is a functional, non-febrile disease of the nervous system 

 characterized by irregular clonic contractions of the voluntary mus- 

 cles, giving rise to movements not under control of the patient. 



What is the morbid anatomy ? 



There are no definite lesions. Some claim the lesions are in 

 the nervous system, while others say they are in the joints. 



Give the aetiology. 



The cause is unknown. It often attacks young and weakly 

 sulDJects, although older animals are affected. It is probably due to 

 some irritation of the nervous system. It may follow punctured 

 wounds of the feet. 



What are the symptoms ? 



In the horse, there is twitching of the muscles of the anterior 

 extremity, those about the eyes, lips, shoulders, feet, etc. 



In the posterior it has been called stringhalt; there is a 

 spasmodic elevation of the extremity. 



How may stringhalt be diagnosed ? 



In the stall, by causing the animal to get from one side of the 

 stall to the other, or by trotting the animal and turning around in a 

 short space. This condition is to be considered an unsoundness. 



What is the prognosis ? 



Usually unfavorable as regards a cure, except it be the result 

 of a punctured wound of the foot, when recovery will take place 

 in the course of a week or ten days. These cases rarely terminate 

 in death, but the course of the disease is somewhat slow. 



What are the indications for treatment ? 



If due to punctured wounds of the feet, it gradually disap- 

 pears by exercise. In other cases, if mild, the symptoms may dis- 

 appear after being driven a short distance, but return after a rest. 



The drugs indicated are the bromides, chloral, morphine. 



