3o6 Veterinary Medicine. 



vived them, fatten and kill as soon as the secondary symptoms 

 commence — about the end of the third or the middle of the fourth 

 month. Damp pastures should be drained and exposed ones 

 sheltered. 



Treatment. In rare cases a spontaneous recovery may ensue 

 in connection with rupture of the scolex from a sudden fall or a 

 blow on the head. Hogg attained the same end by puncturing 

 the cyst with a common knitting needle, introduced through the 

 nose and perforated plate. Youatt passed a long trochar and 

 cannula into the hydated through the same channel. These 

 methods are, however, dangerous and uncertain. A better method 

 is to extract the cyst through a perforation in the cranial wall. 

 If more than one hydated exists it is necessary to repeat the 

 operation. 



If the cranial bone is softened that is selected as the point to 

 perforate. The skin covering it is scrubbed with soap and water, 

 shaved, and rinsed with an antiseptic solution (Mercuric chlo- 

 ride i:iooo). Then a boiled trochar and cannula of }^ inch bore, is 

 pushed in yi inch and the trochar withdrawn. The sheep may 

 be turned on its back to favor the discharge, but it must be firmly 

 held to prevent struggling with its legs or swaying or knocking 

 its head. As the sac is emptied it will protrude through the tube 

 and may be slowly pulled out with a pair of fine forceps. The 

 cannula is now withdrawn and the wound covered with collodion 

 or a pitch plaster. After the operation the patient may be kept 

 in a dark box, secluded and quiet, and upon a laxative diet for 

 ID to 14 days, until danger of shock and inflammation have 

 passed. 



If the bone has not softened the point for perforation must be 

 deduced from the symptons. If the sheep turns in a circle the 

 hydatid will usually be found in the centre of the hemisphere, 

 toward which the turn is made, and the perforation should be in 

 front of the ear and half an inch from the median line of the 

 skull. If the head is elevated and a straightforward advance is 

 made by the patient the perforation must be close to the median 

 line. If the frontal crest is present (in a horned sheep) the per- 

 foration must be behind this, thereby avoiding the frontal .sinus. 

 If the lack of coordination of muscular movement and the exces- 

 sive timidity suggests a hydatid in the cerebellum, the opening 



