PASTURING AND SOILING II9 



satisfactory treatment for bad cases is tapping. This con- 

 sists in making a hole through the skin and muscles, over 

 the prominent swelling on the left side, into the rumen 

 or 'paunch,' thus allowing the gas to escape at once, re- 

 lieving the animal. 



"The best method of tapping is by means of an instru- 

 ment called a trocar and cannula. A trocar is a sharp- 

 pointed instrument, five or six inches long, and about the 

 size of a lead pencil, with a handle at one end. Over the 

 point of the trocar slips a tube, called a cannula, not quite 

 as long as the trocar, with a wide flange around the upper 

 end of the tube, as shown in the illustration herewith. 



TROCAR AND CANNULA 



"To use a trocar and cannula, proceed as follows : Tie 

 the animal so it cannot get away. With a sharp knife, 

 make a small incision through the skin over the promi- 

 nent part of the swelling on the left side. This incision 



Trocar and Cannula 

 should be made about naif way between the point of the 

 hip and the last rib, and should be large enough to admit 

 the trocar and cannula readily. The incision should be 

 made quickly; then the animal will not notice it. After 

 the incision is made the trocar and cannula are pushed 

 quickly in and directed downward, inward, and forward; 

 push the trocar in until the flange of the cannula rests 

 against the skin. Withdraw the trocar and the gas will 

 rush out; that is, it usually does so; occasionally, how- 

 ever, the end of the cannula is plugged up with green 



