PRECAUTIONS DURING AND AFTER BLEEDING. 153 



In many cases the entrance of small quantities of air produces no 

 bad result ; but in others the animal at once begins to sway to and 

 fro, falls to the ground, shows violent cl3spncea, sweats, and may 

 die in a few minutes. 



Sufficient blood having been taken, the skin is closed either with 

 a pin or interrupted suture. In the former case the pin is cautiously 

 removed in thirty-six to forty-eight hours, the parts being supported 

 with the fingers of the left hand whilst those of the right rotate 

 and remove the pin. In closing the wound care must be taken 

 not to exercise much traction on the edges, as this might cause 

 separation of the skin from underlying tissues, and extensive 

 extravasation. Similarl}-, if during bleeding the outer opening be 

 obstructed, blood accumulates 

 under the skin. Such extravasa- 

 tion would be of little con- 

 sequence were it not that by 

 compressing the vein it ma}- lead 

 to thrombus formation, and that 

 it always supplies a favourable 

 medium for the further develop- 

 ment of the micro-organisms which 

 almost inevitabl}' enter. Failure 

 to remember these facts, and to 

 observe necessary cleanliness, ac- 

 count for most cases of suppura- 

 tion and phlebitis and the train 

 of complications which follow 

 them. 



To prevent the animal injuring 

 or infecting the wound, by lean- 

 ing against or rubbing itself on the manger, etc., it should be 

 secured by pillar reins or be tied up short. Nor should it bt 

 worked soon after bleeding, because the pressure of the collar on 

 the vein or the rise in blood-pressure consequent on exertion may 

 cause the lips of the wound to spring open. 



In operating with the spring fleam on the left side, the instrument 

 IS held in the reversed direction— that is, with the blade pointed 

 downwards (Fig. iSi), or the vein may be compressed with the 

 right hand and the fleam held with the left. 



The right jugular is easier to open witn the lancet (Fig. 182). 

 The position of the operator is similar— that is, near the animal's 

 shoulder. After wetting and smoothing the hair the vein is compressed 



Fiu. 182. — Bleeding with the lancet. 



