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formation. Here, by its hooked processes, it finds its way through 

 the walls of the vessels, into the substance of the brain, and there the 

 cyst, or hydatid, is formed. Should the brain of a sheep, or calf, 

 containing this cyst, be given to a dog, tape worms of this particular 

 kind will again be reproduced, and so the cycle of life is carried 

 on. Sheep are more subject to this affliction than any other animal, 

 but 1 have seen a number of young stirks, aged from 12 to 18 months, 

 affected and of these, several recovered after being operated upon. 



570. Symptoms.— The first symptom noticeable, is gradual loss of 

 flesh by the animal, which carries the head on one side, and walks in 

 a circular direction ; or, it may hold the head upwards and backwards, 

 and walk with high-stepping, jerky action. This variation in the 

 symptoms depends upon the part of the brain affected ; if, on the 

 right side of that organ, the animal will circle to the left, and vice- 

 vevsa ; while, if in the middle, the animal steps high and jerky. 



571. Treatment.— Many farmers and shepherds are expert 

 operators for the removal of the cyst. The old method of 

 operation was to determine the position of the cyst by feeling for a 

 softening of the bone. The wool was then clipped off, and the part 

 burnt through with a red-hot poker ; a goose quill was next inserted, 

 and, by its means, the fluid and hydatid sac were removed. A 

 plaster of tar or pitch was next placed over the part and completed the 

 operation. The new form of procedure is to open the parts by means 

 of a fine trocar and canula, and to draw off the fluid with the aid of a 

 syringe, the sac being next removed by a pair of forceps. Success in 

 these operations greatly depends on the locality of the tumour. 



572. Prevention.— Seeing that the disease originates from a tape 

 worm, in the dog, the method of prevention is obvious. Dogs must 

 either be kept off the pastures or else they ought to have periodical 

 doses of worm medicine, and, vv'hile under treatment, it is well to keep 

 them closely shut up. The heads and brains of diseased sheep 

 should be burnt, instead of being given to the dogs, as is generally 

 the case. Applications of salt to the pastures also have a good effect. 



