88 PUNCTURE OF THE INTESTINES. 



flank about equi-distant from the last rib, the extremities of 

 the transverse processes of the lumbar vertebrae and the ex- 

 ternal angle of the ilium in the standing horse ; at the upper- 

 most point of the abdomen in the recumbent animal, that is, 

 at the most prominent part of the distension. After the 

 skin at this place has been clipped or shaved and disinfected 

 grasp the trocar with the index finger and the thumb of the 

 left hand and holding the instrument perpendicular to the 

 body surface, give it a firm, quick blow with the palm of 

 the right hand and drive it through the abdominal wall into 

 the intestine. With a properly constructed trocar of the 

 dimensions suggested in Figure 5 no preliminary puncture 

 with the lancet is required or advisable. The cutting end 

 of the stilette should be ver3' long, tapering and sharp so 

 that it will cut as freely as the lancet. By performing the 

 operation as directed the trocar ordinarily punctures the 



Fig. 5. 



Intestine trocar with sheath. Outside diameter of caaula 3 mm., 

 length of canula, 16 cm. 



caecum. Withdraw the stilette and permit the gas to escape 

 through the canula. The canula may. become occluded by 

 particles of ingesta entering it and these should be removed 

 by reinserting the stilette. The intestine first punctured 

 may collapse and the flow of gas cease while the tympany 

 continues in other parts ; this may be overcome by reintro- 

 ducing the stilette and pushing the trocar through the distal 

 wall of the bowel and into the next section of intestine 

 beyond. If this does not succeed the trocar may be with- 

 drawn and reinserted in a neighboring area or if need be on 

 the opposite side of the animal. In withdrawing the canula 

 replace the stilette and press the skin against the abdomen 



