568 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



curved surgical needle, and some thread. Sterilize the instruments 

 by boiling at a place convenient to the operation. Operate in a 

 place sheltered, so far as possible, from wind and dust and sun, but 

 with plenty of light to work by. The essential feature of the opera- 

 tion is cleanliness of the hands, of the instruments, and of the site 

 of operation. It is useless to perform an operation of this sort in 

 a careless fashion and with little regard for cleanliness, as the al- 

 most inevitable result will be a bacterial infection resulting in the 

 death of the sheep and the loss of the time spent. 



Inject 2 cubic centimeters of water with a one-eighth grain tab- 

 let of cocain dissolved in it at the site of operation, pushing the 

 needle through the skin and then moving it about so as to distrib- 

 ute the cocain all around the operation area. Shear the w r ool close 

 over this area and for some distance around. Have the hands and 

 the site of operation thoroughly cleaned with some antiseptic solu- 

 tion, such as 3 per cent carbolic acid solution (about a tablespoon- 

 ful to the pint), or a solution of 1 to 1,000 potassium permanganate 

 (put the amount of crystals that can be heaped on a quarter into a 

 quart of water). Take the scalpel or knife and make a V-shaped 

 incision with the place to be operated on included between the legs 

 of the V. With the stylet of the trephine pushed out, start to cut, 

 using the stylet to center the trephine. When the cut is started, draw 

 back the stylet and cut till the bone breaks or is sawed through. In 

 animals other than old rams with thick skulls it requires only a few 

 turns of the wrist to accomplish this, and care must be taken not 

 to press too hard. If the piece of bone comes out stuck in the tre- 

 phine it can be removed with the stylet. If it does not come out, 

 lift it out with the knife, breaking or cutting any unsawed ad- 

 hesions. When bleeding occurs, sponge the bleeding parts with a 

 piece of cotton batting or gauze moistened in the 3 per cent solution 

 of carbolic acid or the 1 to 1,000 potassium permanganate solution. 

 Make a cross-shaped cut in the hard membranous covering of the 

 brain with the bent scissors, taking care to cut only the covering and 

 not the brain. 



If the parasite is located right at this point it will push out, 

 oftentimes breaking, and may be grasped with a pair of forceps and 

 drawn out. If it does not push out it may be sought for by insert- 

 ing the forefinger, carefully washed in the antiseptic solution, into 

 the opening and feeling around for a soft spot in the brain. If 

 such a spot is found the finger may be drawn back and the parasite 

 will usually follow it, and may be removed with the forceps. Ac- 

 cording to Pfab (1910), the cavity of the brain from which the 

 parasite was removed should be washed out by means of a syringe 

 until all bleeding stops, even though it takes half an hour for it to 

 stop. A weak antiseptic solution, such as a carbolic acid solution of 

 one-half of 1 per cent, a solution of 1 part of corrosive sublimate to 

 5,000 parts of water, or a 3 per cent borax solution, would probably 

 be satisfactory for this. Tablets of corrosive sublimate sufficient for 

 making solutions of known strength in given amounts of water can 

 be purchased of druggists. Corrosive sublimate is poisonous and 



