142 THE SURGICAL ANATOMY OF THE HORSE 



being careful to so hold the instrument that its point is directed 

 towards that part of the vessel which presents the greatest degree 

 of distension, the edge of the blade being in the direction of 

 the long axis of the vein, a mallet should be taken in the 

 right hand and a firm rap given to the back of the fleam. 

 The whole of the blade should be driven in, since the structure 

 of the instrument is such that the length of the blade indicates 

 the required depth of the incision. 



The size of the fleam selected varies with the size of the 

 animal, the thickness of the skin, and of the muscle at the seat 

 of operation. 



The fleam should be removed before the pressure which caused 

 the vein to be raised is relaxed by removing the fingers. When 

 the latter is done, the pressure should be continued by placing 

 the edge of the receptacle into which the blood is to be drawn, 

 against the vein at the spot where the fingers were at first 

 applied. 



As blood is withdrawn, there is an alteration in the respirations, 

 and the animal frequently sighs. There is dilation of the 

 pupils, and the pulse is increased in rapidity. When these 

 symptoms appear they are evidence of a sufficient quantity of 

 blood having been withdrawn. If the process of withdrawal of 

 blood be continued the animal will collapse and fall. 



The next step is the closure of the wound. It is unnecessary 

 to suture or otherwise treat the slit in the vessel wall. It usually 

 happens that blood ceases to escape from the vessel as soon as 

 the pressure upon the latter is removed. The cutaneous wound, 

 however, should be closed by inserting a pin-suture. Care should 

 be taken, whilst manipulating the skin for this purpose, not to 

 separate the skin from the wall of the vein by applying too 

 much traction. This would permit of blood escaping from the 

 vein into the space between it and the panniculus muscle and 



