INFECTIOUS BULBAR PARALYSIS 251 



The stage of brain irritation sets in from one to two weeks 

 after infestation, and, as a rule, lasts about one week. Usu- 

 ally this stage is overlooked by the shepherd, as most com- 

 monly the symptoms are not marked. Otherwise the sheep 

 present symptoms of excitement, fright, forced movements, 

 and even convulsions; or, on the other hand, may show lan- 

 guor, stupor, irregular gait, and more rarely maniacal symp- 

 toms. 



In the stage of latency, which lasts from three' to six 

 months, the patient appears normal. 



The gid stage usually develops in winter or early spring, 

 and lasts about one month. In this stage the patient shows 

 mental or motor disturbance and often topical symptoms. 

 Quite commonly the first symptoms noted are those 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- 



Digitized by Microsoft® 



