INFEOTIOUS BULBAR PARALYSIS 231 



Quite commonly the first symptoms noted is that of mental 

 disturbance. The sheep appear stupid, and in some instances 

 act like a horse with chronic hydrocephalus. . Later charac- 

 teristic forced movements appear, the sheep running around 

 in circles, trotting across the field with head up and high 

 knee action or they may roll over the long axis of the body 

 using a limb or the head as a pivot. Sometimes the sheep 

 falls suddenly on its side or may fall over backward, the 

 head being held high, with spasms of the muscles of the neck. 

 Epileptiform convulsions, nystagmus, strabismus, and blind- 

 ness are occasional symptoms. In rare instances a soft, 

 fluctuating area appears at the top of the skull which, if 

 punctured, discharges a clear fluid. The disease usually leads 

 to death through brain paralysis and inanition. 



Treatment. — The most important is the prophylaxis which 

 consists in driving out the tapeworm from the dog and pre- 

 venting dogs from obtaining the brains of sheep containing 

 the cyst. An operative treatment consists in trephining and 

 trocaring the cranium over the seat of the cyst and removing 

 its^contents. 



INFECTIOUS BULBAR PARALYSIS. 



Infectious Itching Disease. Mad Itch. Pseudoeabies. 



Definition. — A peculiar infectious disease which manifests 

 itself mainly by marked pruritus of the skin, nervous irri- 

 tability and sometimes paralysis of the throat and general 

 paralysis. 



Occurrence. — Bulbar paralysis was first definitely recog- 

 nized in Hungary in 1902. The disease has been noted in the 

 United States, especially in the Southern States (Alabama), 

 where it is much confused with rabies. 



Etiology. — The cause of the disease is unknown. It may be 

 readily transmitted by inoculating brain tissue from animals 

 which have died of it into healthy cattle, sheep, and goats. 

 Horses and asses do not seem to be as susceptible to artificial' 

 inoculations as other animals. Dogs, cats, rabbits, guinea- 

 pigs, rats, and mice also acquire the disease when injected 

 with virulent material. The virus seems most potent in the 



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