584 RUMENOTOMY. 



be no time for cleansing the point of operation, otherwise the usual 

 precautions are taken. Where the skin is thick, it is best to make 

 the primary incision with a bistoury ; older practitioners were in 

 the habit of using the fleam for this purpose. The trocar is now 

 thrust through the walls of the abdomen and rumen, being directed 

 slightly towards the right. Considerable force is required, and a 

 slight rotary movement should be made. If the operator is of slight 

 stature, it may sometimes be easier to give a smart blow on the in- 

 strument with the open hand. On account of the size and distension 

 of the rumen, it is of no importance how far one thrusts the trocar ; 

 no injury is likely to result, and therefore it may be allowed to enter 

 up to its shield. 



When the stilette is removed the gas rushes out, sometimes under 

 high pressure and mixed with particles of food, which are apt to block 

 the cannula, and require to be removed with the stilette or a probe. 



The cannula is tied in position until fermentation ceases. To 

 make sure of this the cannula may be closed with a cork and the 

 animal watched ; if tympanites fail to recur, the instrument can 

 be removed. Before doing so, however, a few ounces of an unirri- 

 tating antiseptic may be injected ; the stilette is then reintroduced, 

 the skin is held in position with the lingers of the left hand and the 

 whole instrument slowly withdrawn. 



The skin wound requires no particular treatment, though it may 

 be cleansed and covered either with a pitch plaster, or collodion. 

 Bad results seldom follow the use of the trocar in oxen, though 

 digestion may sometimes be impaired by prolonged distension or 

 by the rumen becoming adherent to the abdominal wall. 



The operation is more dangerous in sheep, though it becomes 

 necessary in cases of threatened suffocation. If possible, the long 

 wool should first be clipped away. Where the rumen is punctured 

 with a knife, a thin tube, or an elderberry stem, may be used as a 

 cannula, being introduced into the rumen alongside the blade. The 

 animal must be watched during the whole time the tube remains in 

 position to prevent its being displaced. 



Rumenotomy. In dealing with a rumen distended with a mass 

 of fermenting food containing much gas, when the trocar is no longer 

 of value, rumenotomy, which cattle tolerate very well, can alone 

 give relief. 



The animal is placed with the right side against a wall and fastened 

 up short. To prevent sudden movement or kicking, the hind-limbs 

 may be tied together above the hocks, or a pole held in a sloping 

 direction may be placed in front of the left hind-leg. 



